The correct option is B the whole Council of Ministers resign
The office of Prime Minister is the most powerful office in India. He is the real custodian of all executive authority. He is the Head of the Government. The Prime Minister holds office during the pleasure of the President but in reality, he stays in office as long as he enjoys the confidence of Lok Sabha. Lok Sabha can pass a vote of no-confidence against him and in such a case the Prime Minister either submits his resignation to the President or gets dismissed by the President. Article 75(2) provides that the Ministers shall hold office during the pleasure of the President. The Council of Ministers is collectively responsible to Lok Sabha. It means that if the Ministry loses the confidence of the "Lok Sabha", all ministers including those who are from Rajya Sabha have to go. The entire ministry is obliged to resign. Thus, in parliamentary government ministers remain in office so long as they enjoy conference of the members of the lower house of parliament.