Which One of the Following People Would Not Be Considered

Which one of the following people would not be considered a part of the labor force?

A) A steel worker who was laid off last week and is seeking work.
B) A steel worker who was laid off last year and is no longer seeking work.
C) A student who also works part-time.
D) A member of the U.S. Navy.
E) A retired college professor paid to teach a summer course.