The correct answer is (d) President.
The President of India is the only person who can prorogue the session of the House of the People. The President can do this on the advice of the Prime Minister. The President can also dissolve the House of the People.
The Speaker of the House of the People is the presiding officer of the House. The Speaker is elected by the members of the House. The Speaker has the power to adjourn the House, but cannot prorogue it.
The Attorney General of India is the chief legal adviser to the Government of India. The Attorney General is appointed by the President on the advice of the Prime Minister. The Attorney General has no power to prorogue the House of the People.
The Minister of Parliamentary Affairs is a member of the Union Cabinet. The Minister of Parliamentary Affairs is responsible for the smooth functioning of Parliament. The Minister of Parliamentary Affairs has no power to prorogue the House of the People.