The correct option is B The Chief Justice of India
Before entering upon his office, the President takes an oath in the presence of the Chief Justice of India to:
i) discharge his functions;
ii) preserve, protect and defend the Constitution and the law, and
iii) devote himself to the service and well-being of the people of India.
The President holds office for a term of 5 years from the date on which he enters upon his office.