Which of the following does not fit the description of a public good?

A. AM/FM Radio

B. The Postal Service

C. National Defense

D. A Lighthouse

The answer is A: AM/FM Radio.

AM/FM Radio refers to frequencies that are licensed to organizations by the government through communication authorities, to provide Radio services. AM/FM Radio is not a public good since the organizations have to be licensed to use the frequencies. The radio frequencies are expensive, and the government uses the money paid to license the organizations as sources of income.

The Postal Service is a public good even though people pay a minimal amount to utilize the services. The money paid by the postal service users is used to sponsor the department's operations, but not as a form of profit. National Defense and lighthouse are free; thus, they can be categorized as public goods.