The correct answer is A) federalism.
“The United States in Congress assembled shall never engage in a war, nor grant letters of marque or reprisal in time of peace, nor enter into any treaties or alliances, ... unless nine States assent to the same.”—Articles of Confederation
This quote directly reflects the principle of federalism.
The Articles of Confederation are considered to be the first type of Constitution in the United States. However, the Articles left a weak central government and strong states that kept their sovereignty are were the ones that could collect money through taxation. If the central government, the Congress, needed money, it had to ask for it to the states.