Self-study
Fossilized teeth of an extinct species of herbivorous great ape have on them phytoliths, which are microscopic petrified remains of plants. █████ ████ ██████████ ████ ███████ ███████ ██ ██████ ███ █████ ██ ███ ██████ ███ █████ ████ ████ ████ █████████ ████ ██ █████ ███████
Summary
The author concludes that the diet of a certain extinct ape species must have consisted only of certain plants. His reasoning is that the only remains of plants on their teeth are of those particular plant species.
Notable Assumptions
The presence of certain plant remains on the apes’ teeth could indicate, as the author suggests, that they ate only those plants. However, it’s also possible that other plants were part of their diet, but didn’t leave detectable traces. Therefore, the author must assume that any plant the apes ate would have left remains on their teeth.
26.
The argument assumes which one ██ ███ ██████████
a
None of the █████ ███████ ████ ████ ██████████ ██ ███ █████ █████ ███ █████ ██████ ████████
This is irrelevant, because the author’s argument is about the limited diet of an extinct ape species. Whether any of the plant species it ate subsequently went extinct doesn’t matter.
b
Plants of every ████ █████ ██ ███ ████ ████ ██████████ ██ █████ ██████
If this weren’t true, the apes could have eaten plants that did not leave phytolith traces on their teeth. This would undermine the author’s argument that the apes only ate the plants that left phytoliths on their teeth.
c
Each of the █████ ████████ ███ ██████████ ██ ███ ████ █████ ███████ ██ ██ ██ ███ ███ █████ ██████
The author is concerned with the complete set of all phytoliths found on the apes’ teeth. How they’re distributed between different teeth is irrelevant.
d
Phytoliths have also ████ █████ ██ ███ ██████████ █████ ██ ████ ██ █████ ███████ ████████
The author’s conclusion is about one particular species of ape. Other species’ diets are irrelevant.
e
Most species of █████ ███ █████ █████ ████ █████ ████ ███████ ██ █ ██████ ██████ █████ ██ ███████
The author’s conclusion is about one particular (extinct) species of ape. Other species’ diets are irrelevant.