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.

Example Input: Question: What other artists collaborated on the soundtrack DJ Quik worked on shortly before his friend Mausberg died? Passage:In 1998 Quik released Rhythm-al-ism his fourth studio album on Profile Records. This record was certified Gold in 1999, and contained the singles "Hand in Hand (featuring 2nd II None and El Debarge) and "You'z A Ganxta." It featured guest appearances by Nate Dogg, Snoop Dogg, AMG and Suga Free. That year he went on to produce for The Luniz, Shaquille O'Neal, Deborah Cox and Jermaine Dupri. He also produced on The Kingdom Come by rapper King Tee which ultimately never came out due to label problems. He also faced personal and professional tragedy when his nephew murdered his close friend and protégé Darryl Cortez Reed in 1998. In 1999, there was the release of Classic 220 by 2nd II None, in which Quik played a huge part. Production on Gap Band's Y2K: Funkin' Till 2000 Comz album, Snoop Dogg's No Limit Top Dogg,  and Deep Blue Sea (soundtrack). This was compounded by the death of another friend and rapper Mausberg, subsequently murdered in 2000. That year, saw the release of rapper Mausberg's album, and DJ Quik's Balance & Options. Also production with Whitney Houston, Erick Sermon, 8Ball & MJG, Xzibit and AMG.
 Links: a. Deep Blue Sea (soundtrack) b. Deborah Cox c. Xzibit d. Snoop Dogg
Example Output: a

Example Input: Question: On what date did Apollo 11 land at it's destination site? Passage: are three views of Mare Tranquillitatis on the Moon, taken by the mapping camera of the Apollo 17 mission in 1972, facing south-southwest from an average altitude of 111 km on Revolution 36 of the mission. At the left is the east side of Mare Tranquillitatis, with the craters Franz (bottom right), Lyell (dark floor, right of center), and Taruntius (upper left). The "bay" of dark mare (basalt) at left is Sinus Concordiae, with "islands" of older, light highland material. At the right is the crater Cauchy, which lies between the Rupes Cauchy and Cauchy rille. The center photo shows the central mare with craters Vitruvius (lower right) and Gardner (bottom center). At the horizon are lighter highlands at the southern margin of the mare, near the Apollo 11 landing site. The crater Jansen is visible at the edges of both the center and right photos. The right photo shows the western mare, with the craters Dawes (lower left) and the large Plinius (43 km diameter), with the Plinius Rilles in the foreground. These photos were taken within minutes of each other as the command module America orbited the Moon. The Sun elevation drops from 46 degrees at left to 30 degrees at right.
 Links: a. Apollo 11 b. Apollo 17 c. Lyell (lunar crater) d. Plinius (crater)
Example Output: a

Example Input: Question: What other states joined with Alabama to form the Confederacy? Passage:Alabama was central to the Civil War, with the secession convention at Montgomery, birthplace of the Confederacy, inviting other states to form a Southern Republic, during January–March 1861, and develop constitutions to legally run their own affairs. The 1861 Alabama Constitution granted citizenship to current U.S. residents, but prohibited import duties (tariffs) on foreign goods, limited a standing military, and as a final issue, opposed emancipation by any nation, but urged protection of African slaves, with trial by jury, and reserved the power to regulate or prohibit the African slave trade. The secession convention invited all slaveholding states to secede, but only 7 Cotton States of the Lower South formed the Confederacy with Alabama, while the majority of slave states were in the Union and voted to make U.S. slavery permanent by passing the Corwin Amendment, signed by President Buchanan and backed by President Lincoln on March 4, 1861.
 Links: a. Cotton Belt b. American Civil War c. Cotton Belt d. Union Army
Example Output:
a