Given the task definition, example input & output, solve the new input case.
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: Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin? Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Loduring July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Links: a. Allies of World War II b. Wesel c. Operation Market Garden d. Air Support.
Output: c
The passage describes the 704th's actions during Operation Market Garden.

New input case for you: Question: Which pre-Vietnam War conflicts that the 6th Infantry Regiment participated in last the longest? Passage:The regiment participated in the War of 1812, the MexicanAmerican War, the American Civil War, the Indian Wars (1823-1879), the SpanishAmerican War, PhilippineAmerican War (18991913), the Pancho Villa Expedition (19161917), World War I, World War II, and the Vietnam War. Elements of the 6th Infantry were also part of IFOR, Task Force Eagle, which was charged with implementing the military aspects of the General Framework Agreement for Peace in Bosnia and Herzegovina. In September 1989, the 4th Battalion 6th Infantry deployed to Panama, playing a key role in Operation Just Cause. In January 1994, the 1st Battalion, 6th Infantry deployed to Macedonia for Operation Able Sentry as part of the United Nations Preventive Deployment Force. In May 1998, Company B was deployed again to Bosnia-Herzegovina in support of Operation Joint Endeavor, Operation Joint Forge (OJE/OJF). In 1999, elements were deployed again to Macedonia for the initial launch of support and liberation of Kosovo. In March 2003, Company C, 2nd Battalion deployed with HQ V Corps to Kuwait and participated in the initial invasion of Iraq. The rest of the 2nd Battalion and 1st Battalion deployed to Iraq in late April 2003 as part of 2nd Brigade, 1st Armored Division. The "Regulars" arrived in Baghdad in May 2003 and were the first to relieve elements of the 3rd Infantry Division in Baghdad. The 1st and 2nd Battalions deployed again in support of Operation Iraqi Freedom in November 2005 and April 2008. The 4th Battalion, 6th Infantry deployed in support of Operation Iraqi Freedom/New Dawn from May 2009 to May 2010. In August 2011, the 4th Battalion deployed to Al-Asad and FOB Hammer in Iraq in support of Operation New Dawn. They returned in December of that year when the U.S and Iraqi government failed to come to an agreement concerning soldiers diplomatic immunity, making the Regulars one of the last units to withdraw from the Iraq.
Links: a. Iraq b. War of 1812 c. American Civil War d. Kuwait
Output:
b