The "Young Pioneers" was the name of
a school to teach industrial skills.
all Soviet children under Stalin's rule
a growing group of anti-Stalin activists.
a communist youth organization.

The “Young Pioneers” was the name of D) a communist youth organization.

The "Young Pioneers" was an organization of children which was operated by a Communist Party. Children were expected to enter the organization in elementary school and continue forming part of it into adolescence.
There were several groups of pioneer organizations, including the "Vladimir Lenin All-Union Pioneer Organization" in the Soviet Union, The "Young Pioneers of China", and the "Young Pioneers of America", among others.