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: What was the population of Southampton when Charles Ogston first arrived there? Passage:Ogston was the son of Alexander Milne Ogston of Ardoe, Kincardineshire. He was educated at the Royal Military College, Sandhurst and commissioned a second lieutenant in the Gordon Highlanders in November 1897. He served on the North-West Frontier of India from 1897 to 1898 and took part in the Tirah Campaign under Sir William Lockhart. Promoted to lieutenant on 21 July 1899, he was later the same year sent to South Africa to serve as an intelligence officer in the Second Boer War. He took part in the Relief of Kimberley (February 1900), including the Battle of Magersfontein (11 December 1899), followed by fighting in the Orange Free State from February to May 1900, including the Battle of Paardeberg (18–27 February 1900). In May 1900 he was posted to the Transvaal Republic, where he took part in the occupation of Johannesburg and Pretoria, the capital of the republic, followed by service around the occupied areas, including the Battle of Bergendal (August 1900) and fighting near Lydenburg. He was promoted to captain on 22 January 1902, and following the end of hostilities in early June 1902 left Cape Town on board the SS Orotava, arriving at Southampton the next month.
 Links: a. Siege of Kimberley b. Battle of Bergendal c. Southampton d. Southampton

Ex Output:
c


Ex Input:
Question: How many soldiers died in the battle that Stanley missed due to illness? Passage:He fought at several battles in Missouri, including the Battle of Wilson's Creek, where he guarded the supply trains. President Abraham Lincoln appointed Stanley as brigadier general September 28, 1861, although the U.S. Senate did not confirm the appointment until March 7, 1862. Fighting in the Western Theater, he participated in the operations against New Madrid, Missouri and the Battle of Island Number Ten. He was involved in numerous major battles, including the Second Battle of Corinth, where he commanded a division of infantry of the Army of the Mississippi, and the Battle of Stones River, in which he led the cavalry of the Army of the Cumberland. On March 11, 1863, Stanley was appointed major general to rank from November 29, 1862. Stanley also led the Union cavalry in the Tullahoma Campaign. He fell ill late in 1863 and missed the Battle of Chickamauga. In 1864, he fought under William Tecumseh Sherman as a division commander in the IV Corps of the Army of the Cumberland during the Atlanta Campaign, and he was promoted to command of the corps when Maj. Gen. Oliver O. Howard was named commander of the Army of the Tennessee. After the capture of the city, instead of employing him marching to the sea, Sherman dispatched Stanley and his IV Corps to Tennessee to help protect the state from invasion by John Bell Hood's Army of Tennessee.
 Links: a. Army of Tennessee b. Missouri c. Battle of Chickamauga d. John Bell Hood

Ex Output:
c


Ex Input:
Question: Which of the two rivers closest to where the SR 87 begins is longer? Passage:SR 87 begins on the banks of the Mississippi River in Lauderdale County, just north of the mouth of the Hatchie River. The highway then passes through the community of Fulton, where it has an intersection with SR 207, which provides access to Fort Pillow State Park. SR 87 continues east through wooded areas and passes by the West Tennessee State Penitentiary before coming to the community of Cherry, where it has its first intersection with SR 371. The highway then goes east through farmland and has another intersection with SR 371 before coming to an intersection with US 51/SR 3 and entering the town of Henning. SR 87 enters downtown along Graves Avenue before having a short concurrency with SR 209 (Main Street). SR 87 then leaves Henning along Mc Farland Avenue and passes just south of Durhamville before continuing east and crossing into Haywood County.
 Links: a. Durhamville, Tennessee b. Henning, Tennessee c. Henning, Tennessee d. Mississippi River

Ex Output:

d