The Government of India Act of 1919 clearly defined(2015)
a) the separation of power between the judiciary and the legislature
b) the jurisdiction of the central and Provincial government
c) the power of the Secretary of State for India and the Viceroy
d) None of the above
It relaxed the central control over the provinces by demarcating and separating the central and provincial subjects. The central and provincial legislatures were authorised to make laws on their respective list of subjects. However, the structure of government continued to be centralised and unitary.
It further divided the provincial subjects into two parts—transferred and reserved which is what we know as diarchy.
Source: Laxmikanth – Indian Polity – Chapter 1 (Historical Background)