Q: Generate a correct and concise answer for the question based on the words in the context.
Context : Gerhard Bielig (28 April 1916 -- 29 September 2004) was a German U-boat engineer (Ing.) in World War II and recipient of the Knight's Cross of the Iron Cross (German: Ritterkreuz des Eisernen Kreuzes).
Question : In which war did Gerhard Bielig serve?
A:
World War II