(D) is the correct answer.

Issue: Whether Congress has the power to dictate to the President how the military should be used. Rule: The President is Commander in Chief of the Armed Forces under the U.S. Constitution. Although the scope of this power is not clear, Congress cannot dictate to the President on military matters. Congress has the power to declare war, and to raise and support an army and navy, and to pass emergency legislation once a war is declared, but it does not have the ability to command the Armed Forces.

Analysis: Here it is important to remember the distinction between the war powers held by Congress when compared to the President’s war power: the power to raise and support an army and navy is not the power to command an army and navy. (D) is correct because it recognizes that Congress is attempting to command the army, which is unconstitutional as a violation of separation of powers. (A) is incorrect because the power to raise and support an army and navy is not the power to command the army and navy. (B) is incorrect because previous legislation does not provide justification for new legislation. (C) is incorrect because the power to command the army and navy does not come under the guise of foreign affairs.