He served in the army in ---when he was in ----A.1940's ;his

He served in the army in ___when he was in ____A.1940's ;his twenties B.1940's ;the twenties C.the He served in the army in ___when he was in ____A.1940's ;his twenties B.1940's ;the twentiesC.the 1940's ;his twenties D.the 1940's ;the twenties