We are told that Haffer's hypothesis is that "during the ice ages the Amazon lowlands became a near-desert arid plain; meanwhile, the more elevated regions became islands of moisture and hence served as refuges for the fauna and flora of the rain forest."
The last paragraph states that even though there is "no conclusive proof" for this theory, it has led other researchers to gauge the effects of climatic changes.
So we are asked which of the answer choices is evidence that would contribute to proof of Haffer's explanation.
Answer choice (A) does not work as evidence since the explanation states that the lowlands became an arid desert, whereas (A) states that the water levels rose in the lake, i.e. in the lowlands. This is not compatible with the passage.
Answer choice (B), similar to (A), does not work as evidence, since Haffer's explanation states that the elevated regions became islands of moisture, whereas (B) is stating that it was too cold to support rain forests. Therefore, again, this is not compatible.
Answer choice (C) is irrelevant. We do not know how monsoon rains effect the rain forests overall temperature and climate. Thus, it cannot stand as evidence for Haffer's explanation.
Answer choice (D) does not work as evidence since we know Haffer's explanation states that the lowlands became an arid desert, while the more elevated regions retained more moisture, while (D) states that the uplands, i.e. more elevated regions, show evidence of having an arid landscape. Therefore, this is not compatible.
Answer choice (E) is correct because it shows evidence of the lowlands being an arid desert by having fossilized pollen supporting vegetation that needs little water, i.e. vegetation that would thrive in an arid desert.
Hope that clears things up! Please let us know if you have any other questions.
