This is a pretty tough question. To solve it, remember that in order to strengthen an argument the right answer does NOT have to prove that it is correct, but only needs to make the argument more convincing. In this case, the right answer should give us additional reason to believe that the charred bone fragments indicate that early hominids used fire.

The answer is E. I go through the question in detail in the full solution below (taken from the GMATFix App).



-Patrick

We want an answer that suggests that the bones were charred by campfires (or some similar use of fire) by the Swartkans 1,000,000 years ago. Here's an answer by answer approach.

(A):: We don't care what's happening today, we care about what happened 1,000,000 years ago; out of scope.

(B):: This would actually WEAKEN the argument, if anything: it suggests that the animals may have died in forest fires rather than in campfires started by the Swartkans.

(C):: So what - this would presumably happen if the animals had been burned in a campfire or if they'd been consumed by a forest fire.

(D):: Evidence from 500,000 years ago is nice, but we're dealing with charred bones that are 1,000,000 years old - how do we know that fire was used then?

(E):: This doesn't help much, but it does give us _something_: the suggestion that the Swartkans were able to use cutting tools at the same time that these bones were charred. This suggests that the Swartkans could either have been cutting strips of white stinkwood to use in a fire ... hey, it's something!

This is a great example of a tough CR question: none of the answers are great, so we settle for the least bad answer. (E) gives us something (circumstantial evidence suggesting that the Swartkans could cut down trees for a campfire) and the others give us nothing, so E it is.