The period of dual federalism (1865-1937) was marked by:

a. congressional supremacy in the area of commerce.
b. state-government supremacy in the area of commerce.
c. presidential supremacy in the area of commerce.
d. business supremacy in the area of commerce.
e. national supremacy in the area of commerce.

d. business supremacy in the area of commerce.

Explanation:

Dual federalism (also divided sovereignty) is a political arrangement in which the power of the state is divided between the federal and the state governments in clearly defined terms. This was how the United States government would have been classified in the years between 1865 and 1937. During these years, neither the federal nor the state government dominated commerce. Instead, businesses had supremacy in the area of commerce.