The "Double Shift" Refers to Which of the Following Patterns

The "double shift" refers to which of the following patterns of work in the Soviet Union?

A) The necessity for factory workers to work longer hours to fulfill the quotas of the five-year plans.
B) Women in communist societies working at their jobs and then again in their homes as housewives and mothers.
C) The more relaxed policy toward child labor implemented after Stalin's death when Nikita Khrushchev replaced Georgy Malenkov.