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 what modern day countries did the band of nomads  who visited the Hami Desert live? Passage:Beyond an occasional visit from a band of nomad Mongols, this region of the Pe-shan swelling is entirely uninhabited. And yet it was from this region, according to Grigory Grum-Grshimailo (1889-1890 explorer), that the Yue-chi (Yuezhi), a nomadic people akin to the Tibetans, proceeded when, towards the middle of the 2nd century BC, they moved westwards and settled near Lake Issyk-kul; and from here proceeded also the Shanshani, or people who some two thousand years ago founded the state of Shanshan or Lofi-lan. The ruins of this town were discovered by Sven Hedin in the desert of Lop in 1901. Here, says the Russian explorer, the Huns gathered strength, as also did the Turks (Ch. Tukiu) in the 6th century, and the Uighur tribes and the rulers of the Tangut kingdom. But after Genghis Khan, in the 12th century, drew away the peoples of this region, and no others came to take their place, the country went out of cultivation and eventually became the barren desert it is now. During the Hun time, and probably into the Middle Ages, the present desert was a lush steppe grassland able to support sustainable seasonal nomadic horse husbandry on a large scale.
 Links: a. Shanshan b. Shanshan c. Mongols d. Issyk-Kul
Example Output: c

Example Input: Question: Which is the oldest ancient religious text that mentions Tripura? Passage:Although there is no evidence of lower or middle Paleolithic settlements in Tripura, Upper Paleolithic tools made of fossil wood have been found in the Haora and Khowai valleys. The Indian epic, the Mahabharata; ancient religious texts, the Puranas; and the Edicts of Ashoka – stone pillar inscriptions of the emperor Ashoka dating from the third century BCE – all mention Tripura. An ancient name of Tripura is Kirat Desh (English: "The land of Kirat"), probably referring to the Kirata Kingdoms or the more generic term Kirata. However, it is unclear whether the extent of modern Tripura is coterminous with Kirat Desh. The region was under the rule of the Twipra Kingdom for centuries, although when this dates from is not documented. The Rajmala, a chronicle of Tripuri kings which was first written in the 15th century, provides a list of 179 kings, from antiquity up to Krishna Kishore Manikya (1830–1850), but the reliability of the Rajmala has been doubted.
 Links: a. Puranas b. Haora River c. Upper Paleolithic d. Khowai River
Example Output: a

Example Input: Question: Was the GDP of Egypt larger than that of Syria the year of the Israeli invasion into Lebanon? Passage:According to historians William Cleveland and Martin Bunton, Beirut became an international banking center because of its “laissez-faire economic system”. Business owners from Cairo, Damascus, and Baghdad moved to Beirut for economic opportunities. Despite Lebanon’s cultural liberalism and economic prosperity, sectarian tensions remained as citizens identified themselves through their sects. With Muslims calling for greater representation and with Cold War tensions, Lebanese leadership had to decide whether to ally with the West or with Egypt, Syria and its Arab history. Christians wanted to continue alliances with the West but Muslims were drawn to Nasser's pan-Arabism. Multiple factors including sectarian tensions and Palestinian refugee settlement in southern Lebanon contributed to the beginnings of the Lebanese Civil War. In 1976, Syrian President Hafez al-Assad sent troops into Lebanon to fight PLO forces on behalf of Christian militias. This led to escalated fighting until a cease-fire agreement later that year that allowed for the stationing of Syrian troops within Lebanon. The Syrian presence in Lebanon quickly changed sides; soon after they entered Lebanon they had flip-flopped and began to fight the Christian nationalists in Lebanon they allegedly entered the country to protect. The Kateab Party and the Lebanese Forces under Bachir Gemayel strongly resisted the Syrians in Lebanon. Following the Israeli invasion into Lebanon in 1982, new Lebanese President Amine Gemayel sought the support of Syrian troops to stabilize the region. Syria fought Israeli troops after the latter's invasion of Lebanon.
 Links: a. Bachir Gemayel b. Palestinian refugees c. Egypt d. Syria
Example Output:
c