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: 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
Example Output: a

Example Input: Question: Have any of the original members of Rage Against the Machine ever divorced? Passage:Audioslave's history dates back to October 18, 2000, when Rage Against the Machine's lead vocalist Zack de la Rocha announced he was leaving the band, citing a breakdown in its "decision-making process". This led to the breakup of Rage Against the Machine, but the remaining three members of the bandTim Commerford, Tom Morello, and Brad Wilkdecided to stay together and announced plans to continue with a new vocalist. Several vocalists jammed with the three, including B-Real of Cypress Hill, but they did not want another rapper or anybody who sounded like de la Rocha. Contrary to popular belief, Layne Staley of Alice in Chains neither auditioned nor was asked to join the new project. Tom Morello denied this claim on his Twitter account in 2015. Music producer and friend Rick Rubin suggested that they play with Chris Cornell of Soundgarden. Rubin also persuaded the three of them to go into group therapy with performance coach Phil Towle after the breakup. Rubin was confident that with the right new voice, Rage Against the Machine had the potential to become a better band; he believed "it could turn into a Yardbirds-into-Led Zeppelin scenario." Commerford later credited Rubin for being the catalyst that brought Audioslave together. He called him "the angel at the crossroads" because "if it wasn't for him, I wouldn't be here today."
Links: a. Rage Against the Machine b. Layne Staley c. Zack de la Rocha d. Tim Commerford
Example Output: d

Example Input: Question: How many casualties were there in the battle after which Edward IV's brother was beheaded? Passage:John Courtenay is said to have been originally intended for a career in the church. He was knighted by his brother, Thomas Courtenay, 6th/14th Earl of Devon, after the Battle of Wakefield. After the Battle of Mortimer's Cross, the future King Edward IV of England marched and took the capital from the Lancastrians. Parliament voted an attainder on his opposition, and John declared a traitor. The effect of the attainder was to terminate the Barony of Okehampton (creation 1299), so that the Earldom inherited from the Redvers family was in abeyance, passing laterally to the descendants of Courtenay's sisters The new King, Edward IV, marched north and sealed his reign with the bloody victory at the Battle of Towton, following which his brother was beheaded. About 1465, Courtenay was in exile in France with Queen Margaret of Anjou (wife of King Henry VI of England). He was titular Earl of Devon from 1469.
Links: a. Battle of Wakefield b. Thomas Courtenay, 6th/14th Earl of Devon c. Edward IV of England d. Battle of Towton
Example Output:
d