Correct option is B
Under the Constitution of India, the Constitutional Head of the Executive of the Union is the President. This means that the President is the formal head of the government, but the real power lies with the Prime Minister and the Council of Ministers. The President has the power to appoint the Prime Minister and the other ministers, but they are responsible to the Parliament. The President also has the power to dissolve the Parliament and call for new elections.
The Prime Minister is the head of government and exercises executive powers, but the President is the constitutional head of the executive branch.
The Chief Justice of the Supreme Court is the head of the judiciary and not the executive.
The Speaker of the Rajya Sabha is the presiding officer of the Rajya Sabha, which is the upper house of the Parliament, and does not hold the position of the Constitutional Head of the Executive.