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: Who are the members of the group who collaborated with other singers multiple times for Bob Wills is Still the King? Passage:And in any case, people in Texas came to identify with the song. The work of the Austin-based group Asleep at the Wheel helped to keep popular knowledge of Wills going, and they collaborated with Clint Black on a new version of "Bob Wills Is Still the King" on a 1999 tribute album Ride With Bob. Another recording of the song by Asleep at the Wheel, this time in collaboration with Waylon's son Shooter Jennings together with Randy Rogers and Reckless Kelly, appeared on the 2015 effort . The song itself is collected on several Jennings live sets, compilations, and box sets, including RCA Country Legends (2001 compilation, includes studio version), Live from Austin, TX (recorded 1989, released 2006), and Nashville Rebel (2006 box set including studio version). Perhaps the most unexpected appearance was a performance by The Rolling Stones in Austin in 2006 during their A Bigger Bang Tour. Their arrangement featuring Ronnie Wood playing pedal steel guitar was captured on their 2007 The Biggest Bang concert DVD release.
Links: a. Reckless Kelly b. Asleep at the Wheel c. Asleep at the Wheel d. Randy Rogers Band
Example Output: b

Example Input: Question: What are earthwork mounds made of? Passage:Indigenous peoples inhabited Missouri for thousands of years before European exploration and settlement. Archaeological excavations along the rivers have shown continuous habitation for more than 7,000 years. Beginning before 1000 CE, there arose the complex Mississippian culture, whose people created regional political centers at present-day St. Louis and across the Mississippi River at Cahokia, near present-day Collinsville, Illinois. Their large cities included thousands of individual residences, but they are known for their surviving massive earthwork mounds, built for religious, political and social reasons, in platform, ridgetop and conical shapes. Cahokia was the center of a regional trading network that reached from the Great Lakes to the Gulf of Mexico. The civilization declined by 1400 CE, and most descendants left the area long before the arrival of Europeans. St. Louis was at one time known as Mound City by the European Americans, because of the numerous surviving prehistoric mounds, since lost to urban development. The Mississippian culture left mounds throughout the middle Mississippi and Ohio river valleys, extending into the southeast as well as the upper river.
Links: a. Archaeology b. Collinsville, Illinois c. Earthworks (archaeology) d. Collinsville, Illinois
Example Output: c

Example Input: Question: What was the population of Llantrisant the year that the Original London mint was established? Passage:The Royal Mint is a government-owned mint that produces coins for the United Kingdom. Operating under the name Royal Mint Ltd, the mint is a limited company that is wholly owned by Her Majesty's Treasury and is under an exclusive contract to supply all the nation's coinage. As well as minting circulating coins for use domestically and internationally, the mint also produces planchets, commemorative coins, various types of medals and precious metal bullion. The mint exports to an average of 60 countries a year, making up 70% of its total sales. Formed over 1,100 years ago, the mint was historically part of a series of mints that became centralised to produce coins for the Kingdom of England, all of Great Britain and eventually most of the British Empire. The original London mint from which the Royal Mint is the successor was established in 886 AD and operated within the Tower of London for approximately 800 years before moving to what is now called Royal Mint Court where it remained until the 1960s. As Britain followed the rest of the world in decimalising its currency, the Mint moved from London to a new plant in Llantrisant, Wales where it has remained since.
Links: a. Llantrisant b. Medal c. Commemorative coin d. Tower of London
Example Output:
a