Which of the Following Statements About the UN Secretariat Is

Which of the following statements about the UN Secretariat is true?

A) The Secretariat is the leader of the UN Secretary General (UNSG) , who is an administrator and a person with executive power.
B) The UNSG is nominated by the General Assembly and must be approved by the Security Council.
C) The Secretariat has over 10,000 staff, most of whom work at the UN headquarters in New York.
D) The Secretariat is a bureaucracy led by the UN Secretary General (UNSG) , who is an administrator rather than a person with executive power.