Given the task definition and input, reply with output. 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.

Question: How old was the British Admiral when he took control of the Southeast Asia Command? Passage:At the Potsdam Conference in July 1945, the Combined Chiefs of Staff decided that Indochina south of latitude 16° north was to be included in the Southeast Asia Command under British Admiral Mountbatten. Japanese forces located south of that line surrendered to him and those to the north surrendered to Generalissimo Chiang Kai-shek. In September 1945, Chinese forces entered Tonkin, and a small British task force landed at Saigon. The Chinese accepted the Vietnamese government under Hồ Chí Minh, then in power in Hanoi. The British refused to do likewise in Saigon, and deferred to the French there from the outset, against the ostensible support of the Việt Minh authorities by American OSS representatives. On V-J Day, September 2, Hồ Chí Minh had proclaimed in Hanoi the establishment of the Democratic Republic of Vietnam (DRV). The DRV ruled as the only civil government in all of Vietnam for a period of about 20 days, after the abdication of Emperor Bảo Đại, who had governed under Japanese rule. On 23 September 1945, with the knowledge of the British commander in Saigon, French forces overthrew the local DRV government, and declared French authority restored in Cochinchina. Guerrilla warfare began around Saigon immediately, but the French gradually retook control of the South and North of Indochina. Hồ Chí Minh agreed to negotiate the future status of Vietnam, but the talks, held in France, failed to produce a solution. After over one year of latent conflict, all-out war broke out in December 1946 between French and Việt Minh forces as Hồ Chí Minh and his government went underground. The French tried to stabilize Indochina by reorganizing it as a Federation of Associated States. In 1949, they put former Emperor Bảo Đại back in power, as the ruler of a newly established State of Vietnam.
 Links: a. 16th parallel north b. French Cochinchina c. Office of Strategic Services d. Louis Mountbatten, 1st Earl Mountbatten of Burma

d