<p>OP asked me to comment on this question.</p>
<p>Here is your proposed sentence if you choose (B):</p>
<p>Mainly through the efforts of Jane Goodall, apes were revealed to be not blundering, primitive automatons, but beings with complex and subtle social lives just like us.</p>
<p>As maxkim points out, the contrast here is intended to be between apes’ social lives and our social lives, not precisely between their social lives and “us.” So “us” should be “ours.” </p>
<p>I expect you are imagining that “just like us” modifies the entirety of the preceding clause rather than “social lives.” Here is one example of such syntax:</p>
<p>Just like Bob, Sally loves to go for long walks in the volcano.</p>
<p>Let’s move “Just like Bob” to the end of the sentence.</p>
<p>Sally loves to go for long walks in the volcano, just like Bob.</p>
<p>When this clausal modification exists, we must offset the phrase with a comma, whether it is at the beginning or end of a sentence. Choice (B) doesn’t use a comma, so it’s wrong. Another problem with choice (B) from this perspective is that the case of the object of “like” must be in the same case as the subject of the adjacent clause, i.e., the subjective case. In this example, “Bob” must be in the subjective case in order to agree with “Sally,” which is the subject of “loves.” </p>
<p>“Bob” doesn’t visibly inflect between cases, because it’s a proper noun. “Us,” however, does. In the question at hand, “us” does not agree in case with “apes” because “apes” is the subject of “were revealed.” The subjective alternative is “we.” </p>
<p>Therefore, one may write</p>
<p>Mainly through the efforts of Jane Goodall, apes were revealed to be not blundering, primitive automatons, but beings with complex and subtle social lives, just like we.</p>
<p>But this present a secondary issue. “just like we” in its fully explicated form is “just like we [were revealed to be not blundering, primitive automatons, but beings with complex and subtle social lives]”. This phrase also exists under the modification of “Maily through the efforts of Jane Goodall.” Jane didn’t reveal the complexity of humans’ social lives; no one questions their complexity or subtlety. So the sentence would be illogical at that point, though sound from a technical standpoint.</p>
<p>I hope this helps.</p>