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.

Ex Input:
Paragraph- Sent 1: Before crossing to Asia, Alexander wanted to safeguard his northern borders.
Sent 2: In the spring of 335 BC, he advanced to suppress several revolts.
Sent 3: Starting from Amphipolis, he traveled east into the country of the "Independent Thracians"; and at Mount Haemus, the Macedonian army attacked and defeated the Thracian forces manning the heights.
Sent 4: The Macedonians marched into the country of the Triballi, and defeated their army near the Lyginus river (a tributary of the Danube).
Sent 5: Alexander then marched for three days to the Danube, encountering the Getae tribe on the opposite shore.
Sent 6: Crossing the river at night, he surprised them and forced their army to retreat after the first cavalry skirmish.
Sent 7: News then reached Alexander that Cleitus, King of Illyria, and King Glaukias of the Taulanti were in open revolt against his authority.
Sent 8: Marching west into Illyria, Alexander defeated each in turn, forcing the two rulers to flee with their troops.
Sent 9: With these victories, he secured his northern frontier.
Sent 10: While Alexander campaigned north, the Thebans and Athenians rebelled once again.
Sent 11: Alexander immediately headed south.
Sent 12: While the other cities again hesitated, Thebes decided to fight.
Sent 13: The Theban resistance was ineffective, and Alexander razed the city and divided its territory between the other Boeotian cities.
Sent 14: The end of Thebes cowed Athens, leaving all of Greece temporarily at peace.
Sent 15: Alexander then set out on his Asian campaign, leaving Antipater as regent.
Question: What was Alexander's immediate response when Thebes and Athens rebelled? (A) Razed the city (B) Surrendered (C) Alexander headed south (D) Headed west (E) Barnett (F) Headed south.

Ex Output:
A, C, E, F.

Ex Input:
Paragraph- Sent 1: (CNN) -- Horror-meister, Stephen King calls George Pelecanos "perhaps the greatest living American crime writer."Sent 2: His stories are set in Pelecanos' hometown of Washington, D.C., but this is not the side of the U.S. capitol that you see portrayed on TV with white marble monuments, lawyers and lobbyists.
Sent 3: Pelecanos is more interested in working families struggling to get by, the racial tensions in its ethnic neighborhoods and the low-lifes on the edges.
Sent 4: His crime-writing peers call Pelecanos the "undisputed poet" of Washington's gritty side.
Sent 5: The best-selling and award-winning author is out this week with his 17th and latest novel, "The Cut."Sent 6: It's the first in a new series featuring Iraq war veteran and private investigator Spero Lucas.
Sent 7: When he's not working for a Washington defense attorney, Lucas recovers stolen property for a 40% cut.
Sent 8: Now, a high-profile crime boss hires Lucas to find out who's been stealing from him, and it could turn out to be Lucas' biggest payday or an untimely end.
Sent 9: While Pelecanos made his bones in the noir tradition, there's a definite "Western" feel to "The Cut."Sent 10: The new novel takes place in a morally gray and often violent world.
Sent 11: It's peppered with pitch-perfect dialogue and captures the sights, sounds and taste of Washington in rich detail.
Sent 12: In short, Pelecanos reads like the real deal.
Sent 13: Pelecanos knows a thing or two about capturing the authenticity of urban America with an ethnically and socially diverse cast.
Sent 14: In addition to his success as a novelist, Pelecanos is a producer and writer for HBO's New Orleans-set, "Treme."Sent 15: He was previously a producer and Emmy-nominated writer on the hit series "The Wire" and the miniseries "The Pacific."Sent 16: Read an excerpt from "The Cut" CNN recently spoke to Pelecanos about his new novel.
Sent 17: The following is an edited transcript.
Sent 18: CNN: Tell me more about your new character, Spero Lucas.
Question: Who is a poet, a producer and a crime writer? (A) George Pelecanos (B) Stephen King (C) Maya Angelou (D) Pelecanos (E) Meyers Briggs.

Ex Output:
A, D.

Ex Input:
Paragraph- Sent 1: Imagine you are standing in a farm field in central Illinois.
Sent 2: The land is so flat you can see for miles and miles.
Sent 3: On a clear day, you might see a grain silo 20 miles away.
Sent 4: You might think to yourself, it sure is flat around here.
Sent 5: If you drive one hundred miles to the south, the landscape changes.
Sent 6: In southern Illinois, there are rolling hills.
Sent 7: Why do you think this is?
Sent 8: What could have caused these features?
Sent 9: There are no big rivers that may have eroded and deposited this material.
Sent 10: The ground is capable of supporting grass and trees, so wind erosion would not explain it.
Sent 11: To answer the question, you need to go back 12,000 years.
Sent 12: Around 12,000 years ago, a giant ice sheet covered much of the Midwest United States.
Sent 13: Springfield, Illinois, was covered by over a mile of ice.
Sent 14: Its hard to imagine a mile thick sheet of ice.
Sent 15: The massive ice sheet, called a glacier, caused the features on the land you see today.
Sent 16: Where did glaciers go?
Sent 17: Where can you see them today?
Sent 18: Glaciers are masses of flowing ice.
Question: What couldn't the erosion have been caused by? (A) Wind (B) The ground is capable of supporting grass and trees, so wind erosion would not explain it (C) Avalanches (D) Glaciers (E) A giant ice sheet covered much of the Midwest United States (F) Lakes (G) The erosion couldn't have been from wind or rivers (H) Big river.

Ex Output:
A, B, G, H.