Definition: 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: Question: How many members did the Royal Engineers have the year Monckton-Arundell joined the First Life Guards? Passage:Monckton-Arundell was commissioned a second lieutenant in the Nottinghamshire (Sherwood Rangers) Yeomanry on 1 January 1900, and promoted to lieutenant on 11 June 1902. In 1904, he joined the First Life Guards, the senior regiment of the British Army that makes up the Household Cavalry, where he rose to the rank of colonel. During the First World War he was appointed as adjutant general and quartermaster general. He was of the Royal Artillery (1933–35). In 1933 he was appointed Colonel Commandant of the Honourable Artillery Company (HAC) until 1935, when he relinquished it on appointment as Governor-General of New Zealand. Upon retirement from his post as governor-general he returned as Colonel Commandant of the HAC until his death. He was also appointed Honorary Colonel of the 7th (Robin Hood) Battalion, Sherwood Foresters (later 42nd (The Robin Hoods, Sherwood Foresters) Anti-Aircraft Battalion, Royal Engineers) in 1933.
 Links: a. Household Cavalry b. Royal Engineers c. Life Guards (United Kingdom) d. Robin Hood Battalion
Output:
b