azizbaba wrote:.(B) - "The amount of fresh water available to meet the needs of Earth's population varies significantly from region to region."
The language of (B) says exactly what you say it doesn't say.
So I think you've become so convinced that this question is wrong that you're not reading the wording of it correctly. Take a look at it again - you simply can't argue that it doesn't say it varies significantly/is unevenly distributed
Given by B conditions, that is about the needs of Earth's population (which includes animals and plants), the amount of fresh water available to meet the needs of Earth's HUMAN population still may not vary significantly from region to region.
Maybe, maybe not. But the simple fact that it varies calls into question whether everyone has access to water. It's immaterial if, in reality, there's a perfect distribution for humans.