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: Is the person who served as Lebanese President during 1982 still alive? 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. Israel Defense Forces b. Egypt c. Amine Gemayel d. Cairo
Example Output: c

Example Input: Question: How old was the winner of the 18th season of Celebrity Big Brother when they won? Passage:The third series of the show began on 11 August 2015. The official list of cast members was released on 14 July 2015. This series was filmed in Cancun, Mexico, making this the first series to be filmed outside of Europe. They include four boys: Graham Griffiths, Jayden Robins, Kirk Norcross and Stephen Bear, and four girls: Amy Paige Cooke, Laura Alicia Summers, Megan McKenna and Megan Rees. With the announcement of the line-up it was confirmed that former Geordie Shore cast member and star of the first series, Vicky Pattison, would be making her return as an ex alongside Series 2 star Rogan O'Connor. The Only Way Is Essex cast member Kirk Norcross was also confirmed to be taking part in the series, with his ex-fiancee and Celebrity Big Brother star Cami-Li featuring as his ex. Star of Magaluf Weekender Jordan Davies was also revealed to be taking part in the series, also featuring as an ex. Megan McKenna and Jordan later returned for the fourth series. On 5 January 2016, cast member Megan McKenna entered the Celebrity Big Brother house to compete in the seveneeth series, and on 28 July 2016, Stephen Bear entered the house to compete in the eighteenth series where he left as the winner. Jordan Davies made another return to the show, this time during the fifth series with Jemma and Bear, and Holly also returning as an ex again. In August 2017, both Jemma Lucy and Jordan Davies took part in the twentieth series of Celebrity Big Brother.
Links: a. Stephen Bear b. Stephen Bear c. The Only Way Is Essex d. Ibiza Weekender
Example Output: a

Example Input: Question: Which animal population that the National Parks and Wildlife Act 1972 protects has the larger numbers? Passage:Great Australian Bight Marine National Park is a marine protected area in the Australian state of South Australia located west of the state capital of Adelaide. The national park was proclaimed under the National Parks and Wildlife Act 1972 (SA) by the South Australian Government on 26 September 1996 principally to protect the calving waters of the Southern right whale and the Australian sea lion populations. It consists of two sections occupying the ocean immediately adjoining the coastline up to a distance of and extending from the Western Australia border in the west to a locality known as the Tchalingaby Sandhills in the east. The gap between the two sections is also a protected area known as the Great Australian Bight Marine Park Whale Sanctuary which was proclaimed on 22 June 1995 under the Fisheries Act 1982 (SA). The national park is also part of the group of marine protected areas which are located together in waters within Australian and South Australian jurisdictions within the Great Australian Bight and which is collectively known as the Great Australian Bight Marine Park. Since late 2012, the national park and the whale sanctuary have also been within the boundaries of the Far West Coast Marine Park.
Links: a. Great Australian Bight Marine Park b. Southern right whale c. Government of South Australia d. Protected areas of South Australia
Example Output:
b