Generate a question which can yield the answer mentioned in the input. Generated question must be answered by the answer provided in input, without using any extra knowledge.

Q: Context : Charles Calvin Rogers (September 6, 1929 -- September 21, 1990) was a United States Army officer and a recipient of America's highest military decoration--the Medal of Honor--for his actions in the Vietnam War. 
Answer : Vietnam War

A: In which war did Charles Calvin Rogers fought?
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Q: Context : HD 141937 is a star in the constellation of Libra at a distance of 109 ly. 
Answer : Libra

A: Which was the constellation for HD 141937?
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Q: Context : Otto von Bülow (16 October 1911 -- 5 January 2006) was a German U-boat commander in World War II, and a captain in the Bundesmarine. 
Answer : World War II

A:
In what war was Otto von Bülow in?
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