Situation: The author dismisses a proposal to enforce American child labor laws internationally, by comparing it to the impossibility of applying American minimum-wage laws internationally.
Reasoning: The author here is clearly comparing two situations that, on a fundamental level, aren't that similar. As soon as we spot this pattern, we can zero in on the correct answer. The answer will point out that the author makes a false comparison; that's precisely what choice (B), the correct answer, does.
B is the correct answer