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: How many copies did "My Generation" sell the year it was released? Passage:A deliberate use of acoustic feedback was pioneered by Blues and Rock'n'Roll guitarists such as Willie Johnson, Johnny Watson and Link Wray. According to AllMusic's Richie Unterberger, the very first use of feedback on a commercial rock record is the introduction of the song "I Feel Fine" by the Beatles, recorded in 1964. Jay Hodgson agrees that it was the first chart-topper to showcase feedback distortion, created by John Lennon leaning a semi-acoustic guitar against an amplifier. The Who's 1965 hits "Anyway, Anyhow, Anywhere" and "My Generation" featured feedback manipulation by Pete Townshend, with an extended solo in the former and the shaking of his guitar in front of the amplifier to create a throbbing noise in the latter. Canned Heat's "Fried Hockey Boogie" (off of their 1968 album Boogie with Canned Heat) also featured guitar feedback produced by Henry Vestine during his solo to create a highly amplified distorted boogie style of feedback. In 1963, the teenage Brian May and his father custom-built his signature guitar Red Special, which was purposely designed to feed back.
 Links: a. Anyway, Anyhow, Anywhere b. My Generation c. Boogie with Canned Heat d. Johnny "Guitar" Watson

Ex Output:
b


Ex Input:
Question: How long did the Siege of Boston last? Passage:The Battle of Lexington and Concord was the first conflict in the American Revolutionary War. On April 19, 1775, a force of British Army regulars marched from Boston to Concord to capture a cache of arms that was reportedly stored in the town. Forewarned by Samuel Prescott (who had received the news from Paul Revere), the colonists mustered in opposition. Following an early-morning skirmish at Lexington, where the first shots of the battle were fired, the British expedition under the command of Lt. Col. Francis Smith advanced to Concord. There, colonists from Concord and surrounding towns (notably a highly drilled company from Acton led by Isaac Davis) repulsed a British detachment at the Old North Bridge and forced the British troops to retreat. Subsequently, militia arriving from across the region harried the British troops on their return to Boston, culminating in the Siege of Boston and the outbreak of the war.
 Links: a. Old North Bridge b. Paul Revere c. Siege of Boston d. Isaac Davis (soldier)

Ex Output:
c


Ex Input:
Question: What is the nickname of the Giants player who tied a record by hitting three home runs in one World Series game? Passage:The 2012 World Series was the championship series of Major League Baseball's (MLB) 2012 season. The 108th edition of the World Series, the series was a best-of-seven playoff between the National League (NL) champion San Francisco Giants and the American League (AL) champion Detroit Tigers; the Giants won in a four-game sweep. This marked the Giants' seventh World Series title in franchise history, their second in San Francisco (they won five in New York), and their second in a three-year period (2010–2012). Their World Series sweep was the first by an NL team since the Cincinnati Reds swept the Oakland Athletics in the 1990 series and the first NL sweep not by the Reds since 1963, when the Los Angeles Dodgers swept the New York Yankees. This was also the first World Series since 1988 to feature both of that year's League MVPs (Miguel Cabrera for the AL and Buster Posey for the NL). The Giants' Pablo Sandoval, who in Game 1 tied a record by hitting three home runs in one World Series game, two off Tigers' ace pitcher Justin Verlander, was named the World Series Most Valuable Player (MVP).
 Links: a. 2012 Detroit Tigers season b. Cincinnati Reds c. Pablo Sandoval d. Pablo Sandoval

Ex Output:

c