Question

what were the cheka, which lenin used to deal with those who opposed his rule?
group of mensheviks
group of radical revolutionaries
secret police force
special army unit

Explanation:

The Cheka was established by the Bolsheviks in 1917. It was a security agency. Its main task was to suppress counter - revolutionary activities. It was a secret police force used to deal with opponents of the Bolshevik rule (Lenin's rule at that time). Mensheviks were a political group in Russia, different from the Cheka. A group of radical revolutionaries is a rather broad and inaccurate description compared to its actual nature as a police - like force. And it was not a special army unit.

Answer:

secret police force