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: Which of the two companies that posted previews of Somebody to Love was founded first? Passage:A preview of the video was posted on AOL's PopEater.com, and subsequently on Bieber's VEVO channel, including behind the scenes clips of Bieber with the dancers, and highlights of the video with Usher and in front of a green screen. Bieber said, "It's really awesome to be able to work with professional dancers, you know, people that were in, like, ABDC, and also got an approval from choreographer Jamaica, who said Bieber was "killing it" and that she didn't have to give him any corrections. It made its premiere during the June 17, 2010 results show of the seventh season of So You Think You Can Dance, and was introduced by Usher after his performance of "OMG". It later premiered that night on VEVO and on June 18, 2010 on 20/20at the end of their show. The video features dance crews including, America's Best Dance Crew season 5 winners Poreotics, and Season 3's runner up Beat Freaks, as well as The Syrenz, LXD, Medea Sirkas, solo acts Simrin Player and Bboy Fly, and other dancers and crews. Singer/actress and model Katerina Graham makes a cameo in a scene with Poreotics. Bieber's best friend Ryan Butler, who appeared in the "One Time" video, also appears alongside Bieber, wearing a T-shirt advertising his Twitter account. According to Tamar Antai of MTV News the video "makes vague allusions" to clips for Busta Rhymes' "Pass the Courvoisier, Part II" and Chris Brown's "Wall to Wall". A backpack choreography scene with LXD recalls Usher's 1997 video for "You Make Me Wanna".
Links: a. AOL b. 20/20 (American TV program) c. MTV News d. One Time (Justin Bieber song)
Example Output: a

Example Input: Question: Was the population of Canberra greater than that of Adelaide the year Burbidge was appointed assistant agronomist at Waite Agricultural Research Institute? Passage:In 1943 she was appointed assistant agronomist at the Waite Agricultural Research Institute in Adelaide, where she started working on native pasture species for arid and semi-arid South Australia. She was appointed to the new position of systematic botanist at the CSIRO Division of Plant Industry, Canberra in 1946. At CSIRO she worked on organising and extending the herbarium, first as a research scientist and then as curator and was responsible for laying the foundations of the Herbarium Australiense, later the National Australian Herbarium. She wrote Key to the South Australian species of Eucalyptus L'Her. but had not specialised on the genus. Her professional interest in systemic botany was reflected by her tenure as secretary of the systematic botany committee of the Australian and New Zealand Association for the Advancement of Science from 1948 to 1952. She also edited Australasian Herbarium News until her until 1953, when she took a years leave to be the Australian Botanical Liaison Officer at the Kew Gardens herbarium. While at Kew she photographed and indexed type specimens of Australian plants and made microfilm copies of Robert Brown's notebooks for Australian herbaria.
Links: a. Royal Botanic Gardens, Kew b. Eucalyptus c. Canberra d. CSIRO
Example Output: c

Example Input: Question: How long had the talent agency been operating when they signed He Zhuoyan? Passage:She was educated at the Hangzhou Arts School. She started her career by participating in the Hangzhou Super Girl singing contest in 2005, winning the sixth position among the top ten finalists. The following year, she participated in the Chinese Yahoo Three Directors Star Search programme () and emerged as champion of the Zhang Jizhong category. She signed on with the talent agency Huayi Brothers and started acting in period and wuxia-themed television series produced by Zhang Jizhong. She is best known for her role as one of Wei Xiaobao's seven wives, Shuang'er, in Royal Tramp, a 2008 television series based on Louis Cha's novel The Deer and the Cauldron. She has also attained recognition for her role as Wang Yanyu in Paladins in Troubled Times, an adaptation of Liang Yusheng's novel Datang Youxia Zhuan, and as Moli in Bing Sheng, a television series featuring a fictionalised life story of the ancient Chinese militarist Sun Tzu. She has also served as a spokeswoman and endorser for cosmetic and shampoo product brands, as well as appearing in the Chinese Yahoo television commercial Qianshi Jinsheng Pian () together with Huang Xiaoming, her co-star in Royal Tramp.
Links: a. Huayi Brothers b. Hangzhou c. Sun Tzu d. The Deer and the Cauldron
Example Output:
a