What was the main effect of soldiers' mutiny in the February Revolution?

Correct answer: The government's repressive power weakened

Soldiers' mutiny was decisive because the Tsarist government depended on the army to suppress demonstrations and restore order. When soldiers refused to fire on protesters and many joined them, the government lost much of its coercive strength. This made it difficult for the authorities to control Petrograd and greatly weakened the position of the Tsar and his administration.

Option A is correct because the government's repressive power declined when soldiers stopped supporting it. Option B states the opposite. Option C is wrong because the food crisis did not end immediately, and option D confuses the role of the Duma with the military events. The mutiny helped turn the protests into a successful revolution by removing the government's main means of force. Thus, A follows directly.