Explanation:

The Public Accounts Committee (PAC) is one of the most important parliamentary committees in India, responsible for scrutinizing the government's expenditure and financial accounts. * **Correct Option (A) Speaker of Lok Sabha:** The Chairman of the Public Accounts Committee is appointed by the Speaker of the Lok Sabha. This is a well-established parliamentary convention, and since 1967, the Chairman has traditionally been chosen from the opposition party to ensure effective oversight of government finances. This practice reinforces the committee's role as a watchdog. * **Incorrect Option (B) President:** The President of India is the head of state and performs various constitutional duties, including appointing many high-ranking officials. However, the appointment of the Chairman of a parliamentary committee like the PAC falls under the purview of the presiding officer of the House, which is the Speaker of the Lok Sabha. * **Incorrect Option (C) Prime Minister:** The Prime Minister is the head of the government and the leader of the executive branch. While the Prime Minister holds significant political power, the appointment of the Chairman of the PAC is a legislative function exercised by the Speaker to maintain the independence of parliamentary oversight. * **Incorrect Option (D) Chief Justice:** The Chief Justice of India is the head of the judiciary. The judiciary operates independently of the legislative and executive branches, and the Chief Justice has no role in the appointment of chairpersons for parliamentary committees.