Q. Who among the following is ‘de facto executive’?

[A] President

[B] Vice President

[C] Prime Minister

[D] CAG

Answer: C
Notes:

In the scheme of parliamentary system of government provided by the constitution, the President is the nominal executive authority (de jure executive) and Prime Minister is the real executive authority (de facto executive). In other words, president is the head of the State while Prime Minister is the head of the government.

Sources: Laxmikanth