In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

Ex Input:
Question: Which of the two companies that posted previews  of Somebody to Love was founded first? Passage:A preview of the video was posted on AOL's PopEater.com, and subsequently on Bieber's VEVO channel, including behind the scenes clips of Bieber with the dancers, and highlights of the video with Usher and in front of a green screen. Bieber said, "It's really awesome to be able to work with professional dancers, you know, people that were in, like, ABDC, and also got an approval from choreographer Jamaica, who said Bieber was "killing it" and that she didn't have to give him any corrections. It made its premiere during the June 17, 2010 results show of the seventh season of So You Think You Can Dance, and was introduced by Usher after his performance of "OMG". It later premiered that night on VEVO and on June 18, 2010 on 20/20at the end of their show. The video features dance crews including, America's Best Dance Crew season 5 winners Poreotics, and Season 3's runner up Beat Freaks, as well as The Syrenz, LXD, Medea Sirkas, solo acts Simrin Player and Bboy Fly, and other dancers and crews. Singer/actress and model Katerina Graham makes a cameo in a scene with Poreotics. Bieber's best friend Ryan Butler, who appeared in the "One Time" video, also appears alongside Bieber, wearing a T-shirt advertising his Twitter account. According to Tamar Antai of MTV News the video "makes vague allusions" to clips for Busta Rhymes' "Pass the Courvoisier, Part II" and Chris Brown's "Wall to Wall". A backpack choreography scene with LXD recalls Usher's 1997 video for "You Make Me Wanna".
 Links: a. AOL b. 20/20 (American TV program) c. MTV News d. One Time (Justin Bieber song)

Ex Output:
a


Ex Input:
Question: Who was governor of the state in which Moore studied law in 1856? Passage:He was born in Lewisburg, Virginia in a portion of the state along the Ohio River which became West Virginia in his lifetime. His father had been born in Shenandoah County and moved across the Appalachian Mountains to the Greenbrier County area, but died when Charles was an infant. His paternal grandfather had married a daughter of Joseph Morgan, who helped settle the trans-Appalachian area. His mother, Augusta Delphia Page of Staunton, Virginia, a daughter of Major Charles Page, died in 1844 so Charles and his sister were raised by their uncle, George Moore in Mason County. When Charles was 16, he was sent to Marshall Academy in Huntington, and he would also study with John I Van Meter in Pike County, Pennsylvania, then attend Jefferson College (which later became Washington and Jefferson College) in Canonsburg, Pennsylvania. While at Jefferson College, Charles Moore helped found the Phi Kappa Psi fraternity before graduating in 1853. Moore then briefly attended Union College in New York. Returning to Virginia, he studied law at the University of Virginia and completed the course in 1856.
 Links: a. Washington & Jefferson College b. Staunton, Virginia c. Virginia d. Mason County, West Virginia

Ex Output:
c


Ex Input:
Question: Where is the headquarters of the company that developed the B-52? Passage:Strategic Air Command was formed by the United States Air Force after World War II to provide an active defense against any surprise attack by the Soviet Union. Though it had been an ally against Germany and Japan during World War II, by 1948 the Soviet Union showed a propensity to instigate problems with Britain, France and the United States. In August 1949, the Soviet Union detonated its first nuclear weapon and by the early 1950s had detonated a hydrogen bomb. The war of words between the two superpowers escalated during 1950s and 1960s into a nuclear arms race. By 1970 the United States was using a "Triad Defense System" composed of nuclear submarines armed with nuclear missiles, land based intercontinental ballistic missiles with nuclear warheads and bombers capable of delivering hydrogen bombs on enemy targets. The Boeing B-52 Stratofortress bomber had been designed in the early 1950s by Boeing Aircraft Company to give the United States Air Force the capability of delivering nuclear weapons far inside the territory of Soviet Russia. The planes were to fly at high altitude with enough fuel to hit their target. In May 1960, the Soviet Union made known its capability to shoot such high altitude planes out of the sky by using a surface to air missile to strike CIA pilot Francis Gary Powers' U-2 spy plane over Russian territory. From that point on, the high-altitude B-52 had to be modified to conduct missions at low level, something it was not intended to be.
 Links: a. Boeing b. Boeing c. United States Air Force d. Intercontinental ballistic missile

Ex Output:

a