Teacher: 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.
Teacher: Now, understand the problem? If you are still confused, see the following 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.
Solution: D.
Reason: Obama was born in 1961. His mother was born in 1942 and 1961-1942=19. Therefore, "almost twenty" answers the question sufficiently.

Now, solve this instance: Paragraph- Sent 1: The dermis is the inner layer of skin.
Sent 2: The dermis has blood vessels and nerve endings.
Sent 3: The nerve endings explain why your skin is sensitive.
Sent 4: You can sense pain, pressure, and temperature.
Sent 5: You cut your finger and it starts to bleed.
Sent 6: What has happened?
Sent 7: If your skin bleeds, it means you have cut the dermis layer and damaged blood vessels.
Sent 8: The cut really hurts.
Sent 9: It hurts because of the nerve endings in this skin layer.
Sent 10: The dermis also contains hair follicles and two types of glands.
Sent 11: Hair follicles are structures where hairs originate.
Sent 12: Each hair grows out of a follicle.
Sent 13: Hair passes up through the epidermis.
Sent 14: It then extends above the skin surface.
Sent 15: Oil glands produce an oily substance.
Sent 16: The oil is secreted into hair follicles. 
Question: What is one type of gland found in the dermis? (A) Epidermis (B) Tempeature gland (C) Oil gland.
Student:
C.