Why do governments provide some goods and services in market economies?
a. markets cannot operate without some government involvement.
b. markets are always distorted by laissez-faire policies.
c. they provide politicians with better jobs.
d. all needed services cannot be adequately provided by businesses.

explanation:

cause they can

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.