Which of these functions is carried out exclusively by the federal government?

a. commands the military

b. urban planning

c. tax collection

d. establishment of courts

A. commands the military

Explanation:

Clauses 11, 12, 13 and 14 of the US Constitution determine that Congress has the power to raise and support Armies, to provide and maintain a Navy and to make rules for the government and regulation of the land and naval forces. This makes sense since it would be chaos if each state had the power to create carry out commands in the military.

i confess that there are several parts of this constitution which i do not at present approve, but i am not sure i shall never approve them: for having lived long, i have experienced many instances of being obliged by better information or fuller consideration, to change opinions even on important subjects, which i once thought right, but found to be otherwise. it is therefore that the older i grow, the more apt i am to doubt my own judgment, and to pay more respect to the judgment of others.