In 1928 the soviet union underwent a forced transformation from an agricultural to an industrial economy under
a.
the communist plan.
c.
perestroika.
b.
the five-year plan.
d.
the soviet plan.

This was the first five year plan-the answer is b.

The five year plan lasted from 1928 to 1932 and it was centered around economic goals specified by the then leader of the Soviet Union, Joseph Stalin. It focused on the industrialisation of the production of food, which before was done by farmers manually