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 Q]: 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
[EX A]: c

[EX Q]: Question: What age was Robert I the year the Battle of Bannockburn occurred? Passage:Scottish field armies rarely managed to stand up to the usually larger and more professional armies produced by England, but they were used to good effect by Robert I of Scotland at the Battle of Bannockburn in 1314 to secure Scottish independence. He adopted a policy of slighting castles and made use of naval power to support his forces, beginning to develop a royal Scottish naval force. In the Late Middle Ages under the Stewart kings these forces were further augmented by specialist troops, particularly men-at-arms and archers, hired by bonds of manrent, similar to English indentures of the same period. New "livery and maintenance" castles were built to house these troops and castles began to be adapted to accommodate gunpowder weapons. The Stewarts also adopted major innovations in continental warfare, such as longer pikes, the extensive use of artillery, and they built up a formidable navy. However, one of the best armed and largest Scottish armies ever assembled still met with defeat at the hands of an English army at the Battle of Flodden in 1513, which saw the destruction of a large number of ordinary troops, a large section of the nobility and King James IV.
 Links: a. Royal Scots Navy b. Scotland in the Late Middle Ages c. Manrent d. Robert the Bruce
[EX A]: d

[EX Q]: Question: What is the population of the city Ed Ou was attempting to travel to on October 1, 2016? Passage:On October 1, 2016, U.S. Customs and Border Protection officers detained and questioned Ou for more six hours in the Vancouver International Airport on his way to cover the Dakota Access Pipeline protests for the Canadian Broadcasting Corporation (CBC) as part of a project on Native American healthcare in North America. Ou's intended destination was Bismarck, North Dakota but, after passing through the initial security line at the airport, he was flagged by custom agents for secondary screening and pulled aside. They questioned his purpose for traveling to the United States and when he last visited Iraq, a routine experience for him as a journalist reporting in dangerous regions. He explained that he was on assignment as a photographer to cover the pipeline protests at Standing Rock for the CBC and that he had not been to Iraq in more than a year. He was then detained in a room where he was asked to provide details of his trips to every country he had visited in the last five years and all extremist groups he had come in contact with. Officials then requested that he unlock his three encrypted cell phones to search for images of him "posing with a dead body". After he refused to comply to protect his sources, they denied him entry into the United States, confiscated his phones and other materials, searched his checked baggage, and made photocopies of his reporter's notebook and personal diaries against his wishes. When his phones were returned to him, there was evidence of tampering with the SIM cards suggesting that copies of them may have been made. A border official later stated that his name matched a "person of interest" on an unspecified U.S. federal law enforcement watch list, however, no official reason was provided for his detention aside from it being "classified". Ou's travel rights into the United States have been revoked.
 Links: a. North Dakota b. North Dakota c. Diary d. Native Americans in the United States
[EX A]:
a