The correct answer is (c) Chief Minister.
The Chief Minister is the head of the state government in Arunachal Pradesh. He/She is the leader of the party or coalition that has the majority of seats in the Legislative Assembly. The Chief Minister is appointed by the Governor of Arunachal Pradesh.
The Governor is the head of state in Arunachal Pradesh. He/She is appointed by the President of India. The Governor has the power to dissolve the Legislative Assembly, appoint the Chief Minister, and give assent to laws passed by the Assembly.
The President is the head of state of India. He/She is elected by an electoral college consisting of members of both houses of Parliament and the legislative assemblies of the states. The President has the power to appoint the Prime Minister, dissolve the Lok Sabha, and give assent to laws passed by Parliament.
The Prime Minister is the head of government of India. He/She is appointed by the President and is the leader of the party or coalition that has the majority of seats in the Lok Sabha. The Prime Minister has the power to appoint the Council of Ministers, recommend the President to dissolve the Lok Sabha, and introduce bills in Parliament.