One of the biggest threats to American democratic values has been

A) covert operations on the part of the CIA.
B) restrictive congressional oversight of the intelligence agencies.
C) checks on the president's freedom to conduct needed secret foreign policy.
D) popular democratic protests that have undermined America's credibility in the world.

Covert Operations

Secret activities carried out by governments or organizations usually aimed at influencing conditions in foreign countries without revealing their source.

CIA

Central Intelligence Agency, a civilian foreign intelligence service of the federal government of the United States, tasked with gathering, processing, and analyzing national security information.