Prehistoric Chimpanzee Argument, prep test 23

jillianbliss

I am awesome at this portion of the test and usually score really well, but for some reason cannot understand why the correct answer choice on this question is what it is.

The argument is #6 of Section 2 of Prep Test 23. They discuss prehistoric chimpanzee species, tool use and humans. I won't type the argument out unless y'all need me to, but was wondering if anyone could help explain why the correct answer is C over D.

ENTJ

Is this one of the lesson questions JY has a lecture on?

LSATisland

The answer is in fact (D).

jillianbliss

thanks y'all!

cnguye15

Hi,
I believe it is D.
My understanding of the stimulus is:
Main point: the tool must have been used by human
Support: the tool was found in a savanna. there were prehistoric human there, but chimpanzee lived in forest.
There are two flaws:
first it presumes that the chimpanzee cannot carry their tool in while traveling savanna and left it there.
Second, the topography can change over time. it may be that the savanna was in fact a forest when the chimpanzee was alive and changed.
C is the opposite of the first flaw. Did they replace the term human with chimpanzee, C would be correct.
However, even if C was modified , i would still pick D because it has more direct impact on the argument. By checking the answer, you can negate it and will see that it will completely destroy the argument.
I am studying the fundamentals in LR so this is the best i can do. Is my reasoning correct? Thanks