Q: Generate a correct and concise answer for the question based on the words in the context.
Context : Dietrich von Muller (16 September 1891 -- 3 January 1961) was a German Officer during both World War I and World War II. Just before the end of World War II he was promoted to Generalleutnant and awarded the Knight's Cross of the Iron Cross with Oak Leaves and Swords.
Question : In which war did Dietrich von Muller fight?
A:
World War I