Question

while many russian soldiers were on the front during world war i, most of those who remained behind responded to the february revolution by
leaving the cities to fight on the front.
firing into crowds of peaceful protestors.
joining the riots instead of stopping them.
breaking up the riots and restoring order.

Explanation:

During the February Revolution, soldiers who remained behind in Russia joined the riots instead of suppressing them. This was a significant factor in the fall of the Tsarist regime as the military - which was supposed to maintain order - turned against the government.

Answer:

C. joining the riots instead of stopping them