Final answer:
The Central Intelligence Agency (CIA) is an independent agency that is not part of a cabinet department, distinct from the cabinet-affiliated Department of Defense (DOD) and FBI.
Step-by-step explanation:
The independent agency that is not part of a cabinet department among the options provided is the Central Intelligence Agency (CIA). While cabinet departments, like the Department of Defense, which oversees the Federal Bureau of Investigation (FBI), report to the president and are part of the executive branch, independent agencies such as the CIA and the Environmental Protection Agency (EPA) perform specific tasks, act independently, and report directly to the president or Congress without being beholden to a specific cabinet department. The EPA is also a regulatory agency that, in addition to its independent status, implements and enforces legislation relating to environmental protection.