Justice Mukherjee C. J., speaking for the court, stated "that though the executive power is vested in the president, the president is only a formal or constitutional head of the executive. The real power is vested in the Council of Ministers on whose aid and advise the president acts in the exercise of his functions," in the following case:

The correct answer is B. Ram Jawaya Kapur v. State of Punjab.

In the case of Ram Jawaya Kapur v. State of Punjab, Justice Mukherjee, speaking for the court, stated that while the executive power of the Union is vested in the President, the President acts as a formal or constitutional head. The real executive power lies with the Council of Ministers, who advise and assist the President in exercising their functions. This case established the principle of parliamentary democracy in India, where the Council of Ministers, responsible to the Parliament, holds the real executive power.