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.

Input: Consider Input: Question: How many years did the owner of the private observatory live? Passage:It would seem that Gill's interests lay elsewhere since after a few years he sold the business, and then spent time equipping Lord Lindsay's private observatory at Dun Echt, Aberdeenshire. In 1874, Gill joined the expedition to Mauritius to observe the transit of Venus. Three years later he went to Ascension Island to observe a near approach of Mars and to calculate its distance. While carrying out these laborious calculations, he was notified of his appointment to the Cape Observatory, which, over the following 27 years he was to refurbish completely, turning it into a first-rate institution. Gill was a meticulous observer and had a flair for getting the best out of his instruments. His solar parallax observations with a heliometer and his calculations of distances to the nearer stars, are testimony to his outstanding work. He recruited Robert Innes to the Cape Observatory.
 Links: a. South African Astronomical Observatory b. Aberdeenshire (historic) c. James Lindsay, 26th Earl of Crawford d. South African Astronomical Observatory

Output: c


Input: Consider Input: Question: Who was the leader of Hungary during the Hungarian Revolution of 1848? Passage:The last meetings had revealed the rising antagonism with Britain and France, especially on Italian unification, the right to self-determination and the Eastern Question. The Alliance is conventionally taken to have become defunct with Alexander's death in 1825. France ultimately went her separate way after the July Revolution of 1830, leaving the core of Russia, Austria and Prussia as Central-Eastern European block which once again congregated to suppress the Revolutions of 1848. The Austro-Russian alliance finally broke up in the Crimean War: though Russia had helped to completely destroy the Hungarian Revolution of 1848, Austria did not take any action to support her ally, declared herself neutral and even occupied the Wallachian and Moldavian lands on the Danube upon the Russian retreat in 1854. Thereafter, Austria remained isolated, which added to the loss of her leading role in the German lands, culminating in the defeat of the Austro-Prussian War in 1866.
 Links: a. Eastern Europe b. Hungarian Revolution of 1848 c. Danube d. Wallachia

Output: b


Input: Consider Input: Question: When was the town nearby founded? Passage:Scott was born in Cooksville, Illinois near the town of Normal, Illinois. He lived on a farm until the age of 19 when he entered Illinois State Normal University. He remained at the university for two and a half years while teaching at country schools. With the aid of scholarship, he was able to attend Northwestern University in 1891 where he received a Bachelor of Arts degree in 1895. He desired to become a university president in China, so he enrolled at McCormick Theological Seminary; however, upon his graduation in 1898, he could not find a position. Instead, he decided to go to Germany with his wife and study psychology with Wilhelm Wundt at the University of Leipzig. While there, he received his Doctorate of Philosophy in psychology and education in 1900.
 Links: a. Normal, Illinois b. Normal, Illinois c. Germany d. Doctor of Philosophy


Output: a