The cavalry's refusal to fire on demonstrators broke which basic dependence of Tsarism?

Correct answer: Dependence on army obedience for state repression

Tsarism depended heavily on the army and police to enforce official orders, control crowds and suppress opposition. When cavalry units refused to fire on demonstrators, the government could no longer assume that military personnel would obey every repressive command. This was politically important because the coercive apparatus was the immediate foundation of autocratic rule. The refusal showed that the regime’s instruments of force were beginning to lose discipline or confidence, making repression unreliable. Option A is therefore correct. Peasant harvests, foreign traders and Church education were not the direct mechanisms used to suppress this demonstration, so options B, C and D do not explain the event.