Explanation:

The Prime Minister's Office (PMO) is a staff agency meant for providing secretarial assistance and crucial advice to the Prime Minister. The Prime Minister's Office is headed politically by Prime Minister and administratively by the Principal Secretary. Additionally, it consists of one or two b Additional Secretaries, three to five Joint Secretaries, a number of Directors Deputy Secretaries, and Undersecretaries. There are also other officers like Officers on Special Duty; Private secretaries, and so on. These officers are supported by regular office establishments. Hence, statement 2 is correct. • The major functions of PMO are: o Acting as the ‘think-tank’ of the Prime Minister. o Faster decision-making: It helps in faster decision-making as it involves experienced and powerful decision-makers. Assisting the Prime Minister in respect of his overall responsibilities as head of the government like Maintaining liaison with central ministries/departments and the state governments. o It acts as the residual legatee of the Central Government, that is, it deals with all such subjects which are not allotted to any ministry/department. o However, is not concerned with the responsibilities of the Prime Minister as the chairman of the Union Cabinet. Hence, statement 1 is not correct. • PMO is an extra-constitutional body that has no mention in the Indian Constitution. However, it was given the status of a department under the Government of India Allocation of Business Rules, 1961. However, Unlike Ministries/Departments, no administrative or quasi–judicial decisions are generally taken in the Prime Minister’s Office which may affect a particular person or class of persons. Hence, statement 3 is not correct. • National Authority Chemical Weapons Conventions has been established under the Chemical Weapons Convention Act, 2000 for implementing the provisions of the Convention on the Prohibition of the Development, Production, Stockpiling, and Use of Chemical Weapons and on their Destruction, signed on behalf of the Government of India at Paris on the 14th day of January 1993. NACWC is an office in the Cabinet Secretariat, Government of India. Hence, statement 4 is not correct.