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: His famous series of sixteen great designs for the Apocalypse is dated 1498, as is his engraving of St. Michael Fighting the Dragon.
Sent 2: He made the first seven scenes of the Great Passion in the same year, and a little later, a series of eleven on the Holy Family and saints.
Sent 3: The Seven Sorrows Polyptych, commissioned by Frederick III of Saxony in 1496, was executed by Durer and his assistants c.
Sent 4: Around 1503-1505 he produced the first seventeen of a set illustrating the Life of the Virgin, which he did not finish for some years.
Sent 5: Neither these, nor the Great Passion, were published as sets until several years later, but prints were sold individually in considerable numbers.
Sent 6: During the same period Durer trained himself in the difficult art of using the burin to make engravings.
Sent 7: It is possible he had begun learning this skill during his early training with his father, as it was also an essential skill of the goldsmith.
Sent 8: In 1496 he executed the Prodigal Son, which the Italian Renaissance art historian Giorgio Vasari singled out for praise some decades later, noting its Germanic quality.
Sent 9: He was soon producing some spectacular and original images, notably Nemesis (1502), The Sea Monster (1498), and Saint Eustace (c.
Sent 10: 1501), with a highly detailed landscape background and animals.
Sent 11: His landscapes of this period, such as Pond in the Woods and Willow Mill, are quite different from his earlier watercolours.
Sent 12: There is a much greater emphasis on capturing atmosphere, rather than depicting topography.
Sent 13: He made a number of Madonnas, single religious figures, and small scenes with comic peasant figures.
Sent 14: Prints are highly portable and these works made Durer famous throughout the main artistic centres of Europe within a very few years.
Question: What skill did Durer possibly learn during his early training with his father? (A) The skill of capturing atmosphere (B) The skill of using the burin to make engravings (C) Art of painting (D) The skill of printing (E) The skill of engraving sets (F) Using the burin to make engravings (G) Art of using the burin to make engravings.

Output: B, F, G.

Input: Consider Input: Paragraph- Sent 1: Abrasion is another type of weathering.
Sent 2: Like ice wedging, it is a form of mechanical weathering.
Sent 3: Like ice wedging, abrasion does not change the rock into another type of rock.
Sent 4: With abrasion, one rock or piece of sediment bumps against another rock.
Sent 5: Rocks dont normally roll around on their own, so why do they move?
Sent 6: There are a couple of reasons a rock may move.
Sent 7: Gravity can cause rocks to move.
Sent 8: They may roll downhill or fall off a cliff.
Sent 9: As they roll down a hill, they bump into each other.
Sent 10: Maybe a moving rock hits a rock that is not moving at the bottom of the hill.
Sent 11: Moving water causes rocks and sediment to move.
Sent 12: Rocks are bounced along the bottom and bump against one another.
Sent 13: As they collide, they begin to chip away at each other.
Sent 14: Angular rocks become more rounded with each collision.
Sent 15: Strong winds cause abrasion.
Sent 16: The wind carries sediment.
Sent 17: This sediment is thrown against other rocky surfaces by the wind.
Sent 18: It is like sand-blasting a rock.
Question: What two types of movement could gravity cause in rocks? (A) Collision (B) Levitation (C) Strong winds (D) They may roll downhill (E) To roll downhill or fall off a cliff (F) They may fall off a cliff (G) Circular motion.

Output: D, E, F.

Input: Consider Input: Paragraph- Sent 1: Right after the Pentagon was hit, NEADS learned of another possible hijacked aircraft.
Sent 2: It was an aircraft that in fact had not been hijacked at all.
Sent 3: After the second World Trade Center crash, Boston Center managers recognized that both aircraft were transcontinental 767 jetliners that had departed Logan Airport.
Sent 4: Remembering the "we have some planes" remark, Boston Center guessed that Delta 1989 might also be hijacked.
Sent 5: Boston Center called NEADS at 9:41 and identified Delta 1989, a 767 jet that had left Logan Airport for Las Vegas, as a possible hijack.
Sent 6: NEADS warned the FAA's Cleveland Center to watch Delta 1989.
Sent 7: The Command Center and FAA headquarters watched it too.
Sent 8: During the course of the morning, there were multiple erroneous reports of hijacked aircraft.
Sent 9: The report of American 11 heading south was the first; Delta 1989 was the second.
Sent 10: NEADS never lost track of Delta 1989, and even ordered fighter aircraft from Ohio and Michigan to intercept it.
Sent 11: The flight never turned off its transponder.
Sent 12: NEADS soon learned that the aircraft was not hijacked, and tracked Delta 1989 as it reversed course over Toledo, headed east, and landed in Cleveland.
Sent 13: But another aircraft was heading toward Washington, an aircraft about which NORAD had heard nothing: United 93.
Sent 14: United Airlines Flight 93 FAA Awareness.
Sent 15: At 9:27, after having been in the air for 45 minutes, United 93 acknowledged a transmission from the Cleveland Center controller.
Sent 16: This was the last normal contact the FAA had with the flight.
Sent 17: Less than a minute later, the Cleveland controller and the pilots of aircraft in the vicinity heard "a radio transmission of unintelligible sounds of possible screaming or a struggle from an unknown origin."Sent 18: The controller responded, seconds later: "Somebody call Cleveland?"This was followed by a second radio transmission, with sounds of screaming.
Question: Which flight never turned off its transponder? (A) United Airlines Flight 93 (B) American 11 (C) Delta 1989 (D) The fighter aircraft from Ohio (E) Delta 8919 (F) The American 1989 (G) United 93 (H) UA 93.
Output: C.