Puzzling LR question about Kidney Stones -- help requested Forum

[ComatoseClown]

PT 31 S3 Q2

Paraphrased conclusion:
Ironically, many people through increasing their calcium intake experience a decrease in recurrence, as opposed to an increase.

Given this, Why is A not more correct than D?

D says "decreases the amount to be filtered by the kidneys". But we're not necessarily concerned with amount? This is because the stimulus addresses 'the chances of recurrence, aka frequency,' [of kidney stones], not necessarily the amount of calcium intake to be filtered by the kidneys. (I agree it's definitely true that calcium filtered by the intestines and not the kidneys can lead to less kidney stones, but for the sake of the specific stimulus, aren't we concerned about reducing the chances of RECURRENCE? Choice A seems to do just that -- animal studies indicate that increased calcium take [through the supplements] have resulted in those animals RARELY getting additional stones. Rarely getting additional stones is much closer to the stimulus's "decreased chances of recurrence", than is choice D's "decreased amount of calcium intake needed to be filtered by the kidneys".

Curious to any of your thoughts.

P.S. Isn't it rather surprising to you that this question is only #2 of the section? (Or am I the only one who found it really difficult?)

[Verity]

PM me the question verbatim. Nobody knows what the context is.

[ComatoseClown]

PM me the question verbatim. Nobody knows what the context is.

It's PrepTest 31, Section 3, Question 2, should be in this book http://www.amazon.com/Next-Actual-Offic ... 260&sr=8-1

[suspicious android]

Given this, Why is A not more correct than D?

D says "decreases the amount to be filtered by the kidneys". But we're not necessarily concerned with amount? This is because the stimulus addresses 'the chances of recurrence, aka frequency,' [of kidney stones], not necessarily the amount of calcium intake to be filtered by the kidneys. (I agree it's definitely true that calcium filtered by the intestines and not the kidneys can lead to less kidney stones, but for the sake of the specific stimulus, aren't we concerned about reducing the chances of RECURRENCE? Choice A seems to do just that -- animal studies indicate that increased calcium take [through the supplements] have resulted in those animals RARELY getting additional stones. Rarely getting additional stones is much closer to the stimulus's "decreased chances of recurrence", than is choice D's "decreased amount of calcium intake needed to be filtered by the kidneys".

Curious to any of your thoughts.

Yeah, I think the confusion here is that you're not really trying to explain how to reduce the chances of recurrence. The "discrepancy" in the stimulus is that kidney stones occur when you get too much calcium--but taking more calcium generally reduces the occurrence of kidney stones. WTF??? The question asks us to focus on that weird fact, and find something that explains it.

Answer choice (A) just says that animals that take extra calcium don't get more kidney stones. Yeah, just like in humans. But why the heck does the extra calcium stop them from getting more stones? I'm still weirded out by that.

Answer choice (D) says taking calcium may increase calcium levels in the intestines, but reduce it in the kidneys. Oh, that makes sense, I see why taking more calcium prevents a problem caused by too much calcium.

Gotta be really focused on what the question stem is asking you to do here. Answer choice (A) is appealing if you're looking for something that is consistent with the stimulus, or a fact that might bring about the situation seen in the stimulus, but does nothing to resolve the discrepancy.

[senorhosh]

D says "decreases the amount to be filtered by the kidneys". But we're not necessarily concerned with amount? This is because the stimulus addresses 'the chances of recurrence, aka frequency,' [of kidney stones], not necessarily the amount of calcium intake to be filtered by the kidneys. (I agree it's definitely true that calcium filtered by the intestines and not the kidneys can lead to less kidney stones, but for the sake of the specific stimulus, aren't we concerned about reducing the chances of RECURRENCE? Choice A seems to do just that -- animal studies indicate that increased calcium take [through the supplements] have resulted in those animals RARELY getting additional stones. Rarely getting additional stones is much closer to the stimulus's "decreased chances of recurrence", than is choice D's "decreased amount of calcium intake needed to be filtered by the kidneys".

Calcium filtered through intestines leads to less kidney stones, which exactly means less chance of recurrence. We ARE concerned about the amount of calcium. The stimulus states that kidney stones are produced by overly concentrated calcium (or, in another words, the amount). This means that less amount (or concentration) of calcium means the kidneys will not be overly concentrated, and thus, will have a less likely chance of kidney stones (recurrence).

A is a shell answer. Sure it seems to make sense. But the experiment was done on ANIMALS. The stimulus is talking about people. Yes, there is a difference. The stimulus never says that these tests apply to humans and the test makers knew people would assume this.

Hope that helps. Also, this applies for future questions!! There will be multiple questions which subtly change one word to another just like this. Make sure to read each and every word. I remember there was another question that talked about "dogs", and the shell answer talked about "animals". The answer was wrong for the same reason.

[totaltest.milan]

Choice A doesn't explain the paradox, it gives you information that reinforces it. Think of it this way, if you were to take out the last sentence in the stimulus and replace it with the choice you'd still have a paradox. The question still remains, how is it that these animals have less chance of getting kidney stones once they take supplements if kidney stones form when urine produced in the kidneys is overly concentrated with calcium?

Also, recurrence means additional kidney stones, and additional kidney stones are a result of the amount of calcium in the kidneys.

[senorhosh]

Choice A doesn't explain the paradox, it gives you information that reinforces it. Think of it this way, if you were to take out the last sentence in the stimulus and replace it with the choice you'd still have a paradox. The question still remains, how is it that these animals have less chance of getting kidney stones once they take supplements if kidney stones form when urine produced in the kidneys is overly concentrated with calcium?.

oh right. this too

[ComatoseClown]

Thanks for the solution and the invaluable insight guys, now it makes sense!