Answer:
Executive privilege.
Step-by-step explanation:
If the Congress is investigating U.S. involvement in the civil war in Argentina and they demand the President turns over to them information given to him or her by the State Department and the CIA. The president refuses, asserting the right of executive privilege.
The executive privilege is the assertion of the right to withhold certain information from the court or congress by the president.
It basically, provides immunity for the president from matters relating to foreign affairs, the military and national security.