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: In which country is the seaport city of Porto located where the wine received its name "port"? Passage:Port is produced from grapes grown and processed in the demarcated Douro region. The wine produced is then fortified by the addition of a neutral grape spirit known as aguardente to stop the fermentation, leaving residual sugar in the wine, and to boost the alcohol content. The fortification spirit is sometimes referred to as brandy but it bears little resemblance to commercial brandies. The wine is then stored and aged, often in barrels stored in a Lodge (meaning "cellar") as is the case in Vila Nova de Gaia, before being bottled. The wine received its name, "port", in the later half of the 17th century from the seaport city of Porto at the mouth of the Douro River, where much of the product was brought to market or for export to other countries in Europe. The Douro valley where port wine is produced was defined and established as a protected region, and the name Douro thus an official appellation, in 1756, making it the third oldest, after Chianti (1716) and Tokaj (1730).
Links: a. Barrel b. Tokaji c. Vila Nova de Gaia d. Porto
Example Output: d

Example Input: Question: Who owns the network that the Busy World of Richard Scarry is currently airing on? Passage:The Busy World of Richard Scarry is an American/Canadian/French animated children's television series, produced by CINAR Animation (now known as DHX Media, previously Cookie Jar Entertainment) and France Animation in association with Paramount Television, which aired from 1994 to 1997, first on Showtime, later on Nickelodeon, and ran for 65 episodes. The television series was based on the books drawn and written by Richard Scarry. Reruns of the show formerly aired in syndication as part of the Cookie Jar Kids Network block, but the show now continues to air on the Cookie Jar Toons block on This TV until October 26, 2013. Reruns of the show aired on Qubo from May 13, 2013, to September 25, 2016. However, it returned to Qubo on March 28, 2017, as part of the network's Night Owl block until May 26, 2018, and currently airs on Light TV.
Links: a. Paramount Television b. Cookie Jar Group c. Light TV d. Children's television series
Example Output: c

Example Input: Question: Which of Hypnotize's singles sold the most copies? Passage:The second part of the double album, Hypnotize, was released on November 22, 2005. Like Mezmerize, it debuted at No. 1 in the US, making System of a Down, along with The Beatles, Guns N' Roses, and rappers 2Pac and DMX, the only artists to ever have two studio albums debut at No. 1 in the same year. In February 2006, System of a Down won the Grammy for Best Hard Rock Performance for "B.Y.O.B.", beating out other established artists such as Nine Inch Nails and Robert Plant. Their second single off the Hypnotize album, "Lonely Day" was released in March in the United States. System of a Down released "Kill Rock 'N Roll" and "Vicinity of Obscenity" as their next promo singles. The band headlined Ozzfest 2006 in cities where tour founder Ozzy Osbourne opted not to appear or was not playing on the main stage (with the exception of the show at Randall's Island, where Ozzy Osbourne headlined the second stage before System of a Down's performance that night).
Links: a. B.Y.O.B. (song) b. Hypnotize (album) c. Hypnotize (album) d. Promotional recording
Example Output:
a