Two of the secret revolutionary groups in russia were

The two secret revolutionary groups in Russia were the nihilists and the populist. The most radical difference between them was their perception of science. The most traditional populist supporters reject science because they thought being full time to the demand of the people was more important. On the other hand, the nihilist argued that the science was the basis of every progress, they had positivism ideas. They saw themselves as free individuals, they thought chasings this freedom was more important than the social one, they were focused on the individual development. Populist supported the farm socialism and the nihilists the industrialism.

pretty sure a is right