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.

Input: Consider Input: Paragraph- Sent 1: Speed is an important aspect of motion.
Sent 2: It is a measure of how fast or slow something moves.
Sent 3: To determine speed you must know two things.
Sent 4: First, you must know how far something travels.
Sent 5: Second, you need to know how long it takes to travel that far.
Sent 6: Speed can be calculated using this formula: speed = distance time A familiar example is the speed of a car.
Sent 7: In the U.S., this is usually expressed in miles per hour.
Sent 8: Think about a trip you and your family made in the car.
Sent 9: Maybe the trip covered 120 miles and it took 3 hours.
Sent 10: What was the cars speed?
Sent 11: speed = 120 mi = 40 mi/h 3h The speed of a car may also be expressed in kilometers per hour (km/h).
Sent 12: The SI unit for speed is meters per second (m/s).
Sent 13: This is the unit of measure a scientist would use.
Question: What is speed? (A) How long it takes to travel that far (B) Speed is an important aspect of motion (C) The measure of gravity against time (D) It is a measure of how far something is (E) Gravitational pull (F) When something moves (G) A force of gravity (H) How far something travels (I) An aspect of motion, it is the measure of how slow or fast something travels (J) How quick something moves in space (K) It is a measure of how fast or slow something moves (L) A measure of how fast or slow something moves (M) The measure of motion (N) An aspect of motion; a measure of how fast or slow an object moves.

Output: B, I, K, L, N.

Input: Consider Input: Paragraph- Sent 1: When a stream or river slows down, it starts dropping its sediments.
Sent 2: Larger sediments are dropped in steep areas.
Sent 3: Some smaller sediments can still be carried by a slow moving stream or river.
Sent 4: Smaller sediments are dropped as the slope becomes less steep.
Sent 5: Alluvial Fans In arid regions, a mountain stream may flow onto flatter land.
Sent 6: The stream comes to a stop rapidly.
Sent 7: The deposits form an alluvial fan.
Sent 8: Deposition also occurs when a stream or river empties into a large body of still water.
Sent 9: In this case, a delta forms.
Sent 10: A delta is shaped like a triangle.
Sent 11: It spreads out into the body of water.
Question: What might you find when a mountain stream flows onto flatter land and comes to a rapid stop in arid regions? (A) Delta (B) Drop off (C) Sand bar (D) Alluvial Fans (E) Deposits.

Output: D.

Input: Consider Input: Paragraph- Sent 1: Eric , a young boy , is excited about his birthday after reading a book and believes that a train will come for him , despite his sister Jill's disbelief .
Sent 2: A few hours later , the train station's control tower wakes up and in the roundhouse , Tillie , a young little blue switcher engine , along with her best bird friend , Chip , wakes up four other trains : Georgia , a kind all-purpose engine , Farnsworth , a stuck-up passenger engine , Jebediah , a worn-out old engine , and Pete , a gruff , burly freight engine .
Sent 3: After the tower assigns Farnsworth and Pete their jobs , Tillie tries to help with the milk train assigned to Jebediah , but the tower insists that she is too small for the job .
Sent 4: Georgia is assigned to pull the birthday train .
Sent 5: A clown named Rollo leads the toys into the train , including Stretch , a basketball player ; Missy , a ballerina ; a Handy Pandy , a panda ; Perky , an elephant ; and Grumpella , a stuffed bird .
Sent 6: During her journey , Georgia breaks down and is taken back to the roundhouse by Doc .
Sent 7: Left behind , Rollo eventually takes Doc's advice of flagging down one of the other engines returning from their daily runs over the mountain .
Sent 8: Farnsworth and Pete turn down their offers to pull the train .
Sent 9: Meanwhile , Tillie asks the tower to rescue the stranded train , but he insists that Tillie will never do the job .
Sent 10: Jebediah turns down his offer to pull the train because of his age , and returns to the roundhouse .
Sent 11: Chip and Tillie sneak past the sleeping tower and pulls the birthday train up a mountain .
Question: What's the name of the clown who's left behind? (A) Doc (B) Chip (C) Rollo.
Output: C.