You are given a paragraph, with numbered sentences, and a question. Write the numbers of the sentences needed to answer the given question. Separate multiple sentence numbers with a comma (", "). E.g. "1, 2" would be the correct response if Sent 1 and Sent 2 are needed to answer the given question (do not include sentences that contain no information that is necessary to answer the question). Sort the sentence numbers in an increasing order (i.e., '1, 2', instead of '2, 1'). Your answer should not contain anything than the sentence numbers separated by a comma (e.g. '1, 2, 3, 4'). The given question requires more than one sentence to answer. So, your answer must contain at least one comma (", ").

Paragraph- Sent 1: According to the radar reconstruction, American 77 reemerged as a primary target on Indianapolis Center radar scopes at 9:05, east of its last known position.
Sent 2: The target remained in Indianapolis Center's airspace for another six minutes, then crossed into the western portion of Washington Center's airspace at 9:10.
Sent 3: As Indianapolis Center continued searching for the aircraft, two managers and the controller responsible for American 77 looked to the west and southwest along the flight's projected path, not east-where the aircraft was now heading.
Sent 4: Managers did not instruct other controllers at Indianapolis Center to turn on their primary radar coverage to join in the search for American 77.
Sent 5: In sum, Indianapolis Center never saw Flight 77 turn around.
Sent 6: By the time it reappeared in primary radar coverage, controllers had either stopped looking for the aircraft because they thought it had crashed or were looking toward the west.
Sent 7: Although the Command Center learned Flight 77 was missing, neither it nor FAA headquarters issued an all points bulletin to surrounding centers to search for primary radar targets.
Sent 8: American 77 traveled undetected for 36 minutes on a course heading due east for Washington, D.C. By 9:25, FAA's Herndon Command Center and FAA headquarters knew two aircraft had crashed into the World Trade Center.
Sent 9: They knew American 77 was lost.
Sent 10: At least some FAA officials in Boston Center and the New England Region knew that a hijacker on board American 11 had said "we have some planes."Sent 11: Concerns over the safety of other aircraft began to mount.
Sent 12: A manager at the Herndon Command Center asked FAA headquarters if they wanted to order a "nationwide ground stop."Sent 13: While this was being discussed by executives at FAA headquarters, the Command Center ordered one at 9:25.
Sent 14: The Command Center kept looking for American 77.
Sent 15: At 9:21, it advised the Dulles terminal control facility, and Dulles urged its controllers to look for primary targets.
Sent 16: At 9:32, they found one.
Sent 17: Several of the Dulles controllers "observed a primary radar target tracking eastbound at a high rate of speed" and notified Reagan National Airport.
Sent 18: FAA personnel at both Reagan National and Dulles airports notified the Secret Service.
Question: What target remained in Indianapolis Center's airspace, then crossed into the western portion of Washington Center's airspace at 9:10.
1, 2.

Paragraph- Sent 1: The little party in the cabin, so disastrously begun, finished, under the mellowing influence of wine and woman, in excellent feeling and with some hilarity.
Sent 2: Mamie, in a plush Gainsborough hat and a gown of wine-coloured silk, sat, an apparent queen, among her rude surroundings and companions.
Sent 3: The dusky litter of the cabin set off her radiant trimness: tarry Johnson was a foil to her fair beauty; she glowed in that poor place, fair as a star; until even I, who was not usually of her admirers, caught a spark of admiration; and even the captain, who was in no courtly humour, proposed that the scene should be commemorated by my pencil.
Sent 4: It was the last act of the evening.
Sent 5: Hurriedly as I went about my task, the half-hour had lengthened out to more than three before it was completed: Mamie in full value, the rest of the party figuring in outline only, and the artist himself introduced in a back view, which was pronounced a likeness.
Sent 6: But it was to Mamie that I devoted the best of my attention; and it was with her I made my chief success.
Question: What task took more than three hours to complete?.
3, 5.

Paragraph- Sent 1: Zinni feared that Bin Ladin would in the future locate himself in cities, where U.S. missiles could kill thousands of Afghans.
Sent 2: He worried also lest Pakistani authorities not get adequate warning, think the missiles came from India, RESPONSES TO AL QAEDA'S INITIAL ASSAULTS 135 and do something that everyone would later regret.
Sent 3: Discussing potential repercussions in the region of his military responsibility, Zinni said, "It was easy to take the shot from Washington and walk away from it.
Sent 4: We had to live there."Sent 5: Zinni's distinct preference would have been to build up counterterrorism capabilities in neighboring countries such as Uzbekistan.
Sent 6: But he told us that he could not drum up much interest in or money for such a purpose from Washington, partly, he thought, because these countries had dictatorial governments.
Sent 7: After the decision-in which fear of collateral damage was an important factor- not to use cruise missiles against Kandahar in December 1998, Shelton and officers in the Pentagon developed plans for using an AC-130 gunship instead of cruise missile strikes.
Sent 8: Designed specifically for the special forces, the version of the AC-130 known as "Spooky"can fly in fast or from high altitude, undetected by radar; guided to its zone by extraordinarily complex electronics, it is capable of rapidly firing precision-guided 25, 40, and 105 mm projectiles.
Sent 9: Because this system could target more precisely than a salvo of cruise missiles, it had a much lower risk of causing collateral damage.
Sent 10: After giving Clarke a briefing and being encouraged to proceed, Shelton formally directed Zinni and General Peter Schoomaker, who headed the Special Operations Command, to develop plans for an AC-130 mission against Bin Ladin's headquarters and infrastructure in Afghanistan.
Sent 11: The Joint Staff prepared a decision paper for deployment of the Special Operations aircraft.
Sent 12: Though Berger and Clarke continued to indicate interest in this option, the AC-130s were never deployed.
Sent 13: Clarke wrote at the time that Zinni opposed their use, and John Maher, the Joint Staff 's deputy director of operations, agreed that this was Zinni's position.
Sent 14: Zinni himself does not recall blocking the option.
Sent 15: He told us that he understood the Special Operations Command had never thought the intelligence good enough to justify actually moving AC-130s into position.
Sent 16: Schoomaker says, on the contrary, that he thought the AC-130 option feasible.
Sent 17: The most likely explanation for the two generals' differing recollections is that both of them thought serious preparation for any such operations would require a long-term redeployment of Special Operations forces to the Middle East or South Asia.
Sent 18: The AC-130s would need bases because the aircraft's unrefueled range was only a little over 2,000 miles.
Question: What is the most likely explanation for the two generals' differing recollections about the AC-130 Option?.
17.