Q: You will be given a context, a subject and a relation. Your task is to generate a question based on the subject and relation. The generated question should include the given subject. Try to use a minimum number of words that are not present in either context, subject or relation while generating question.
Context : The M18 recoilless rifle was a 57 mm shoulder fired anti-tank recoilless rifle used by the U.S. Army in World War II and the Korean War.
Subject : M18 recoilless rifle
Relation : service entry
A:
In which year was the service entry date for M18 recoilless rifle?