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: 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)

Ex Output:
a

Ex Input:
Question: During what years was the Early Bronze Age? Passage:Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to 7000 BC. The south-western and western part of the Iranian Plateau participated in the traditional Ancient Near East with Elam, from the Early Bronze Age, and later with various other peoples, such as the Kassites, Mannaeans, and Gutians. Georg Wilhelm Friedrich Hegel calls the Persians the "first Historical People". The Medes unified Iran as a nation and empire in 625 BC. The Achaemenid Empire (550330 BC), founded by Cyrus the Great, was the first true global superpower state and it ruled from the Balkans to North Africa and also Central Asia, spanning three continents, from their seat of power in Persis (Persepolis). It was the largest empire yet seen and the first world empire. The Achaemenid Empire was the only civilization in all of history to connect over 40% of the global population, accounting for approximately 49.4 million of the world's 112.4 million people in around 480 BC. They were succeeded by the Seleucid, Parthian, and Sasanian Empires, who successively governed Iran for almost 1,000 years and made Iran once again as a leading power in the world. Persia's arch-rival was the Roman Empire and its successor, the Byzantine Empire.
Links: a. Bronze Age b. Cyrus the Great c. Persepolis d. Central Asia

Ex Output:
a

Ex Input:
Question: How old does the tree which the Senegalese impart great importance on typically live? Passage:Traditional African religions like the Serer religion (A at Roog) are adhered to by devout worshippers of Roog the supreme deity in Serer religion. The Serer ethnic group who adhere to the tenets of Serer religion (including those Senegalese who syncretize) honour the Serer pangool and have ancient rituals and festivals devoted to them. The religious affairs of Serer religion devotees are usually headed by the Saltigue (the Serer priestly class) which in ancient times was the preoccupation of the Serer lamanic class. Some of these religious festivals or ceremonies include the Ndut (rite of passage), Xooy (divination festival once a year in Fatick), and the Raan festival. Senegalese hold several ancient beliefs, such as small efforts of 'thanks' or demands, such as protection from water. They also place great importance on the Baobab tree, which is known as the "House of the Spirits." The baobab tree along with other sacred trees figure prominently in the Serer creation narrative. Among the Jola people, some religious festivals include the Samay, Kumpo and the Niasse.
Links: a. Adansonia b. Jola people c. Serer creation myth d. Syncretism

Ex Output:
a