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.
One example is below.
Q: 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.
A: D.
Rationale: Obama was born in 1961. His mother was born in 1942 and 1961-1942=19. Therefore, "almost twenty" answers the question sufficiently.
Q: Paragraph- Sent 1: Oh no!
Sent 2: Your younger sister just mixed up all of your LEGO parts.
Sent 3: Now you have to put them all back into the original categories.
Sent 4: How will you do this?
Sent 5: You sort them by size and shape until they are each back into their specific place in the tray.
Sent 6: What do you think you could have called the mess your younger sister created?
Sent 7: Thats right, it is a mixture.
Sent 8: Fortunately, it was a physical change and she just made a simple mixture.
Sent 9: You are able to separate them back into order.
Sent 10: Its a good thing she did not toss them into the fireplace.
Sent 11: That would have caused a chemical change as they all melted together.
Sent 12: If your LEGOs were melted, you would be out of luck for building that next big project. 
Question: Tossing the LEGOs in the fireplace would have cause what type of change? (A) A melting chemical change (B) A physical change (C) A simple change with the mixture of shapes (D) A chemical change.
A:
A, D.