The National Security Agency (NSA) is authorized to produce in accordance with objectives, requirements and priorities established by the Director of National Intelligence (DNI) with the advice of the National Foreign Intelligence Board.
a. Signals Intelligence (SIGINT)
b. Operational Control (OPCON)
c. Human Intelligence (HUMINT)
d. Combatant Command, Command Authority (COCOM)

a. Signals Intelligence (SIGINT

Explanation:

Signals intelligence can be defined as the process of gathering intelligence by interception of signals through communications that occur between people or from electronic signals that is not directly used in communication which is why it is often gotten from electronic signals as well as the systems used by foreign targets due to the fact that it provides a vital window for the nation.

Therefore SIGNAL INTELLIGENCE (SIGINT) is vital because it provide information gained and retained through the collection and analysis of the electronic signals and communications of a given target which is why the National Security Agency (NSA) is authorized to produce SIGNAL INTELLIGENCE (SIGINT) in accordance with objectives, requirements and priorities established by the Director of National Intelligence (DNI) with the advice of the National Foreign Intelligence Board.

you should try adrenaline. it kicks in in situations like this.