Q8 - Fossilized bones from the hominids Australopithecus

[uhdang]

A bit unclear on why A) is the answer. And here is my thought process.

Important pieces in this stimulus are:
- robustus contained lower ratio of strontium to calcium than did the erectus bones.
- Lower ratio of strontium to calcium in fossilized hominid bones, the more meat the hominid had in its diet.
- erectus is known to have eaten meat.

When connecting these three pieces, we can conclude that robustus have had more meat in its diet than erectus. And from this, we can infer A).
At first, I was sort of hesitant to pick A) and essentially eliminate other answer choices to verify my choice, because I was wondering if there could have been other sources of calcium and strontium that could have made difference. However, I settled this issue from the fact that erectus is known to have eaten meat. Still, since A) is about the diet of robustus, we could probably argue that we are not given anything to support their consumption of meat. So, I was wondering if I am missing anything, or we should be making an assumption of robustus having consumed meat from erectus' being known to have consumed meat.