Since we're looking for a claim strongly supported by the stimulus, we need to be clear on what the stimulus actually says. We can accept everything in the stimulus as true as we search for the answer choice those facts support. The stimulus is discussing fossilized hominid bones, and tells us:

(1) fossilized A. robustus bones have a lower strontium to calcium ratio than fossilized H. erectus bones;
(2) the lower the strontium to calcium ratio in a fossil, the more meat the hominid ate; and
(3) H. erectus ate meat.

Given these facts, we need to find a claim they strongly support. This means we need a direct support relationship, without needing to make assumptions or bring in new information. In other words, the correct answer choice will stay within the scope of the stimulus to make a claim that is strongly supported based only on the information given.

Here, we can also make an inference up-front: that A. robustus ate meat. We know that H. erectus ate meat, but A. robustus had a lower strontium to calcium ratio, which indicates it ate more meat than did H. erectus. We can hunt for this inference in the answer choices, but we should also be ready to pivot to process of elimination if we don't find what we're looking for.

When assessing each answer choice, we can quickly eliminate anything that relies on new information—for example, an answer choice discussing species other than A. robustus and H. erectus. We can also eliminate answer choices that are merely compatible with the stimulus—those that could be true, but also could be false. When we find the correct answer, we should be able to point to the specific facts in the stimulus that support it.