The correct answer is (d). Appointing the Prime Minister is not a constitutional prerogative of the President of India. The President of India appoints the Prime Minister as the leader of the party or coalition that has a majority in the Lok Sabha. The President also appoints other members of the Council of Ministers on the advice of the Prime Minister.
(a) Returning an ordinary Bill for reconsideration: The President can return an ordinary Bill for reconsideration to the Houses of Parliament if he/she is satisfied that it is not in accordance with the Constitution or that it does not contain a provision which the President considers necessary for the peace, security or good government of India.
(b) Returning a financial bill for reconsideration: The President can return a financial bill for reconsideration to the Houses of Parliament if he/she is satisfied that it is not a money bill or that it contains a provision which the President considers unnecessary or undesirable.
(c) Dissolving the Lok Sabha: The President can dissolve the Lok Sabha at any time on the advice of the Prime Minister. However, the President cannot dissolve the Lok Sabha during the first six months of its existence.