They must learn that an object still exists even though they can’t see it.
I believe the answer is d.
Answer:
E. strengthen a claim by indicating that it applies even to exceptional cases
Explanation:
Answer E
Correct. In this sentence, the author makes the claim that melancholy can make one’s imagination “torpid” (sluggish), and that lack of appropriate occasions can prevent the mind from coming up with “sallies and excursions” (clever remarks). He strengthens the claim by extending it to the most exceptional cases when he indicates that it applies to any mind “however volatile,” that is, even to those that are normally the liveliest and most wide-ranging.
