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: 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)

Ex Output:
a


Ex Input:
Question: In what country is the Nikos Kazantzakis Stadium located? Passage:The «Nikos Kazantzakis» Stadium (), formerly known as Ergotelis Stadium and more commonly as Martinengo Stadium, is a football stadium located on the Martinengo bastion, part of the fortifications of Heraklion, on the island of Crete. It is named after Modern Greek literature giant Nikos Kazantzakis, whose grave is also located on the same bastion. It is part of the Ergotelis Athletic Centre, a sport facilities complex owned by Greek multi-sport club Ergotelis. Built in 1946, as Ergotelis Stadium (), it was the traditional home ground of Greek football club Ergotelis until 2004, when the club moved to the Pankritio Stadium, Heraklion's largest and most modern sports venue. The complex currently houses the Ergotelis Youth Academy, the largest youth sports academy on the island of Crete, and one of the largest in Greece, while the stadium itself is still used as the home ground of multiple Heraklion football clubs playing in the Heraklion Football Clubs Association amateur league system. It has a capacity of about 1,000 spectators, of which approximately 600 can be seated.
 Links: a. Crete b. Stadium c. Heraklion d. Crete

Ex Output:
a


Ex Input:
Question: Was the waverly route entirely within the Scottish borders? Passage:The Waverley Route spawned a series of branches serving the towns and villages in the Scottish Borders: a branch line from Kelso Junction near reached Kelso where it met an NER branch from . The NBR Chairman, Richard Hodgson, sought to link the Waverley Route with the Edinburgh-Berwick line between Ravenswood Junction, north of St Boswells, and ; the branch between Reston and Duns had been completed in 1849 and a western section to St Boswells was promoted as the Berwickshire Railway. It opened throughout on 2 October 1865. Other towns to be connected were Jedburgh by the independent Jedburgh Railway which was inaugurated on 17 July 1856 and worked by the NBR, and Selkirk via the Selkirk and Galashiels Railway, also opened in 1856 and operated by the NBR, while Langholm received a branch from , and Gretna one from . One of the last branches to be constructed was the Lauder Light Railway in 1901; this replaced an omnibus subsidised by the NBR providing access from the town of Lauder, famed for its trout, and connecting with trains at .
 Links: a. Lauder b. Jedburgh c. Selkirk and Galashiels Railway d. Scottish Borders

Ex Output:

d