In which of the following Act or reforms the dyarchy was abolished?

In which of the following Act or reforms the dyarchy was abolished?

مندرجہ ذیل میں سے کس ایکٹ یا اصلاحات میں بادشاہت کو ختم کیا گیا؟
Explanation

Diarchy is a form of government characterized by corule, with two people ruling a polity together either lawfully or de facto, by collusion and force.