The Purges Were a Series of Trials Based on the Opportunity

The Purges were a series of trials based on the opportunity to do which of the following except:

A) Stalin's desire to remove old supporters of Lenin from the Party.
B) the plan to remove Red Army officers suspected of treason.
C) spread the terror to the lower levels of the population.
D) prepare the population for a dictatorship of the proletariat.
E) all of the above