Option 1 states that the Ministries/Departments of the Union Government are created by the Prime Minister. This statement is incorrect. The creation of Ministries/Departments is done by an act of the Parliament, as per the provisions of the Constitution. The Prime Minister is responsible for allocating portfolios to different Ministers, but the creation of Ministries/Departments does not rest solely with the Prime Minister.

Option 2 states that the Cabinet Secretary is the Ex-officio Chairman of the Civil Services Board. This statement is correct. The Cabinet Secretary, who is the head of the Indian Administrative Service (IAS) and the top-ranking civil servant in India, also serves as the Chairman of the Civil Services Board. The Civil Services Board is responsible for managing the career progression and training of civil servants.

Therefore, the correct answer is option 2 - "2 only".