I feel you. We might be able to infer some answers to (E) based on the author's complaints about organicism, but do you have any line references you can point to for (E)?
(A) 36-41
(B) 4-8
(C) 15-21 (defining characteristic), and 25-27 (accompanying characteristic)
(D) 14-22
If you look at where "separating out the parts for study" is mentioned (such as lines 1-3 or line 46), you can't find any mention of advantages to doing so.
This answer is designed to be tempting because the author IS defending the analytic method and critiquing the organicists. But all we get is the author saying NEGATIVE things about organicism and defending the analytic method in regards to the fact that the analytic method DOES still try to study the properties of the whole.
We never hear POSITIVE things about what good it is to separate out the parts (it's just easy for our brains to think of possible answers to this question on our own).