Teacher:Generate a correct and concise answer for the question based on the words in the context.
Teacher: Now, understand the problem? Solve this instance: Context : Waldemar Mehl (7 September 1914 in Gravenwiesbach, Hesse--29 March 1996 in Wiesbaden) was a German U-boat commander during World War II, and recipient of the (German: Ritterkreuz des Eisernen Kreuzes).
Question : What war was Waldemar Mehl in?
Student:
World War II