You are given a paragraph, a question and some answer options (associated with "A", "B", "C", "D", etc.) You need to list all the correct answer options with their associated letters (e.g. "A" can be a valid answer). Note that sometimes, more than one option can answer the question correctly and completely. In those cases, please generate all such options separated by a comma (e.g. "A, B" is a valid answer). Do not generate anything else apart from one or more of the following characters: 'A', 'B, 'C', 'D', etc.
Example: Paragraph- Sent 1: Obama was born on August 4, 1961, at Kapiʻolani Maternity & Gynecological Hospital in Honolulu, Hawaii.
Sent 2: He is the only President to have been born in Hawaii.
Sent 3: He was born to a white mother and a black father.
Sent 4: His mother, Ann Dunham (1942-1995), was born in Wichita, Kansas, of mostly English descent, with some German, Irish, Scottish, Swiss, and Welsh ancestry. Question: How old was Obama's mother when he was born? (A) teenager (B) in his 40s (C) mid 20s (D) almost twenty.
Example solution: D.
Example explanation: Obama was born in 1961. His mother was born in 1942 and 1961-1942=19. Therefore, "almost twenty" answers the question sufficiently.

Problem: Paragraph- Sent 1: At length, as I entered the pass, the huge rocks began to close around in all their wild, mysterious impressiveness, when suddenly, as I was gazing eagerly about me, a drove of gray hairy beings came in sight, lumbering toward me with a kind of boneless, wallowing motion like bears.
Sent 2: I never turn back, though often so inclined, and in this particular instance, amid such surroundings, everything seemed singularly unfavorable for the calm acceptance of so grim a company.
Sent 3: Suppressing my fears, I soon discovered that although as hairy as bears and as crooked as summit pines, the strange creatures were sufficiently erect to belong to our own species.
Sent 4: They proved to be nothing more formidable than Mono Indians dressed in the skins of sage-rabbits.
Sent 5: Both the men and the women begged persistently for whisky and tobacco, and seemed so accustomed to denials that I found it impossible to convince them that I had none to give.
Sent 6: Excepting the names of these two products of civilization, they seemed to understand not a word of English; but I afterward learned that they were on their way to Yosemite Valley to feast awhile on trout and procure a load of acorns to carry back through the pass to their huts on the shore of Mono Lake. 
Question: Why was he inclined to turn back? (A) Neck pain (B) Fear (C) He was inclined to turn back because a drove of gray hairy beings came in sight, lumbering toward him with a kind of boneless, wallowing motion like bears.

Solution: C.