Q: 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.
Context : ''Karl-Gerat'' (040/041) (German literally ''Karl-device''), also known as Morser Karl, was a World War II German self-propelled siege mortar (Morser) designed and built by Rheinmetall.
Answer : World War II
A:
What is the war during which Karl-Gerat was in the armed forces?