Which of the following (is) are considered market failure(s) ?

A) Monopoly.
B) Externalities.
C) The lack of public goods and services.
D) All of the choices are considered market failures.

All of the choices listed are considered market failures.

A monopoly represents a market failure because it results in decreased competition, higher prices, and lower output.

Externalities, such as pollution or noise, are considered market failures because they impose costs or benefits on individuals who did not choose to incur them, thus resulting in inefficient market outcomes.

The lack of public goods and services, such as national defense or basic research, are also considered market failures because they are likely to be under-provided by the private sector due to the difficulty of excluding non-payers and the free-rider problem.