Why was soldiers joining protesters decisive for the end of Tsarism in the February Revolution?

Correct answer: When army loyalty broke, the Tsar's power of repression weakened

The Tsarist state depended heavily on the army and police to suppress strikes and demonstrations. At first, the authorities expected troops to disperse the crowds in Petrograd. However, many soldiers were themselves exhausted by war, angry about shortages and drawn from peasant families suffering at home. When soldiers refused to fire and began joining the protesters, the government lost its most important instrument of coercion. The demonstrations could therefore expand instead of being crushed. This change also showed that the monarchy no longer possessed reliable support within the armed forces, making abdication and the formation of a Provisional Government possible. Option A is correct because it identifies the breakdown of military loyalty as the decisive loss of state power. The Land Decree belonged to the later Bolshevik period, and the other alternatives are unrelated or false.