Hi bli,
One problem with answer choice (E) is that it presumes that the example given in the prompt (not all courses which take a historical perspective must be taught be a history professor) is an actual policy applied to the university's history professors. In fact, there is no evidence that the university has this policy in place at all.
Another problem with answer choice (E) is that a course can still "take a historical approach" without being a course
about history. For example, a literature course may emphasize how an author was influenced by historical factors without making history the entire focus of the course. By contrast, it seems like the course Statistics for the Social Sciences is still, at heart, a course about math.
Answer choice (E) doesn't accurately apply the facts from the prompt. The "policy" about history courses is just an analogy, not an actual policy in place at the university.
I hope this makes sense! Good luck studying!