Post Civil War, the Doctrine of Dual Federalism Meant

Post Civil War, the doctrine of dual federalism meant

A) a significant increase in the powers of the national government.
B) a "return to normalcy" for many.
C) continued expansion of the North's wartime powers.
D) allowing the national government to regulate all state actions affecting African Americans.
E) allowing the state and national governments to interfere in each other's areas of influence.