You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For consistency, answers should be in all lower cased letters.
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Question: Category: STAGE NAMES 
Clue: Riley is the first name of this guitarist whose stage initials stand for "Blues Boy"

Answer: b.b. king


Question: Category: BELGIUM, BELARUS OR BELIZE 
Clue: It's part of the British Commonwealth of Nations

Answer: belize


Question: Category: "HEAVEN" & "HELL" 
Clue: Carol line following "Holy infant so tender and mild"

Answer:
"sleep in heavenly peace"