Step 1: Understanding the Concept:
The question asks about the constitutional authority responsible for appointing the Governor of a state in India.
Step 2: Detailed Explanation:
According to Article 155 of the Constitution of India, the Governor of a State is appointed by the President by warrant under his hand and seal. The Governor holds office during the pleasure of the President. Although the President makes the appointment, it is done on the advice of the Union Council of Ministers, headed by the Prime Minister. However, the constitutional appointing authority is the President.
Step 3: Final Answer:
The President of India appoints the Governor of a state.