Bob Got A's and Bill Got C's During Their Three

Multiple Choice

Bob got A's and Bill got C's during their three years of Russian class in the late 1940s. What will have happened to their competence at Russian if they have not used it since 1950?

A) Bob will have remained competent at almost his original level until the 1960s, but Bill will have lost most of what he learned by that time.
B) Bob will have remained more competent than Bill for about 10 years, but after that the two will be about the same.
C) Bob's competence will hardly decline until he reaches advanced old age, but Bill will show virtually no competence even in the 1960s.
D) The competence of both will decrease rapidly for a few years, but when they level off Bob will remain substantially more competent than Bill.