You will be given a definition of a task first, then some input of the task.
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: Who was the leader of the Royal Green Jackets in 1966? Passage:The King's Royal Rifle Corps was an infantry rifle regiment of the British Army that was originally raised in British North America as the Royal American Regiment during the phase of the Seven Years' War in North America known as 'The French and Indian War.' Subsequently numbered the 60th Regiment of Foot, the regiment served for more than 200 years throughout the British Empire. In 1958, the regiment joined the Oxfordshire and Buckinghamshire Light Infantry and the Rifle Brigade in the Green Jackets Brigade and in 1966 the three regiments were formally amalgamated to become the Royal Green Jackets. The KRRC became the 2nd Battalion, Royal Green Jackets. On the disbandment of the 1st Battalion, Royal Green Jackets in 1992, the RGJ's KRRC battalion was redesignated as the 1st Battalion, Royal Green Jackets, eventually becoming 2nd Battalion, The Rifles in 2007.
Links: a. Green Jackets Brigade b. Royal Green Jackets c. Green Jackets Brigade d. Rifle Brigade (The Prince Consort's Own)
Output:
b