Detailed Instructions: 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.
Problem:Question: Which of the regiments that Ellwood served in was the largest? Passage:Ellwood graduated from Duntroon in 1990 and was commissioned into the Royal Australian Infantry Corps. His early career included postings as a platoon commander in the 2nd/4th Battalion, Royal Australian Regiment and as an instructor in field training and tactics at Duntroon, before he was seconded to the British Army from 1998 for a two-year exchange with the Irish Guards, then stationed in Germany. During the secondment he deployed as part of the NATO intervention in the Kosovo War in 1999, serving as second-in-command of an armoured infantry company in the King's Royal Hussars Battle Group. For his service in Kosovo, Ellwood was awarded a Commander British Forces Commendation. He returned to Australia as a company commander and operations officer in the 5th/7th Battalion, Royal Australian Regiment (5/7RAR). Ellwood commanded B Company on operations in East Timor from October 1999 to April 2000, when 5/7RAR deployed with the International Force East Timor.
 Links: a. 2nd/4th Battalion, Royal Australian Regiment b. Kosovo War c. 2nd/4th Battalion, Royal Australian Regiment d. King's Royal Hussars
Solution:
a