Top Law Schools

P: The mere threat of renewed competition will prevent the company from raising its prices to unreasonable levels.
C: Predatory pricing practice should be acceptable

Which one of the following is an assumption on which argument depends? (NA)

"E" Any pricing practice that does not result in unreasonable prices should be acceptable.

I don't understand how can "E" be NA. Negated "E" sounds like this - Some pricing practices that does not result in unreasonable prices should be unacceptable. It doesn't destroy the conclusion since argument is concerened only with "predatory pricing" practice. There could be other practices that does not result in unreasonable prices but nevertheless are unacceptable.

Please help!

Try looking at the core from this angle:

• PREMISE: Predatory pricing would not result in unreasonable prices.
  CONCLUSION: Predatory pricing should be acceptable.

You're absolutely correct that the negation of (E) would be "some pricing practices that do not result in unreasonable prices should be unacceptable." But if that's true, then how is the author concluding on the basis of the 'lack of unreasonable prices' that predatory pricing must be acceptable? That conclusion is not supported by the premise, since now we know that 'lack of unreasonable prices' could mean unacceptable.

You're right that the argument is only concerned with predatory pricing, and it's possible that we could still get to the conclusion with (E) negated, but we would need some new information/evidence to get us there. The existing premise will no longer offer any support for the conclusion. Remember that the negation test does not necessarily make the conclusion false - it just makes it a dumb/unsupported thing to conclude on the basis of the premise alone.

What do you think?

I understand why "E" is right answer now, thank you