Thanks for the question! So this question is asking us for the primary purpose of the passage. Now, let’s take a look at what (E) says. The primary purpose of the passage is to detail the thematic concerns in the work of a particular writer (here, Toni Morrison) and identify the sources of those concerns. Is that what happens here? Does the passage really even discuss the thematic concerns in Jazz? Obviously, they’re mentioned, but are they really discussed at all? No. And are the sources of those concerns mentioned either? Also no. So those can’t be the primary purpose of the passage, and so (E) has to be the wrong answer here.
Hope this helps! Feel free to ask any other questions that you might have.