The correct answer is B. the president.
The President of India has the power to prorogue the Lok Sabha. Prorogation is the formal ending of a session of Parliament. It is done by the President on the advice of the Prime Minister. The President can prorogue the Lok Sabha at any time, but he/she must consult the Prime Minister before doing so.
The Speaker of the Lok Sabha is the presiding officer of the House. He/she is elected by the members of the House. The Speaker has the power to adjourn the House, but he/she cannot prorogue the House.
The Prime Minister is the head of the government of India. He/she is appointed by the President. The Prime Minister has the power to advise the President to prorogue the Lok Sabha.
The Minister for Parliamentary Affairs is a member of the Council of Ministers. He/she is responsible for the smooth functioning of Parliament. The Minister for Parliamentary Affairs does not have the power to prorogue the Lok Sabha.