One Reason for the Decline of the U

One reason for the decline of the U.S.labor force participation rate for men since 1959 is that

A) women entering the labor force have discouraged male workers.
B) technology has created many new white-collar jobs with flexible work hours.
C) an increase in wealth allowed some men to retire early.
D) fewer men pursued higher education.
E) the number of part-rime jobs has decreased.