The correct answer is (b).
Article 61 of the Constitution of India provides for the procedure for the removal of the President of India through the process of impeachment. It states that the President may be removed from office on the ground of proved misbehaviour or of incapacity, but only upon a resolution passed by both Houses of Parliament, supported by a majority of not less than two-thirds of the members present and voting in each House.
The motion for impeachment must be initiated in the House of the People, and if it is passed by a majority of the members present and voting, it is then transmitted to the Rajya Sabha. The Rajya Sabha then has to consider the motion, and if it is passed by a majority of the members present and voting, the President stands removed from office.
The President cannot be removed from office during the period of his absence from India on leave of absence.
The impeachment process is a very serious matter, and it is only to be resorted to in cases of grave misconduct or incapacity on the part of the President.