The Government of the United Kingdom domestically referred to as Her Majesty's Government is the central government of the United Kingdom of Great Britain and Northern Ireland. Act of 1919:The Act introduced a diarchy (rule of two individuals/parties) for the executive at the level of the provincial government. The diarchy was implemented in eight provinces:Assam, Bengal, Bihar and Orissa, Central Provinces, United Provinces, Bombay, Madras and Punjab. The provincial governments were given more powers under the system of the Dyarchy. The governor was to be the executive head in the province. Hence, the correct answer is the Act of 1919.