Question

the role of cabinet secretaries
how is the modern department of defense different from the old department of war?
it is a cabinet department and not an independent executive agency.
it was not created by any act of congress, unlike the department of war
it contains sub - departments for the air force, army, and navy.
it is no longer concerned with defending the nation through military force.

Explanation:

The Department of Defense was created in 1947 by the National Security Act. It combined the War Department (which became the Department of the Army) and the Department of the Navy (which included the Marine Corps) and added the Department of the Air Force. So it contains sub - departments for the Air Force, Army, and Navy.
The Department of War was also a cabinet - level department (not an independent executive agency), both were created by acts of Congress, and the Department of Defense is still concerned with national defense through military force.

Answer:

It contains sub - departments for the Air Force, Army, and Navy.