Answer:
D. The free-rider problem
Step-by-step explanation:
The free-rider problem is when a person who benefits from a service, public good or project doesn't pay for the service or doesn't pay the fair value.
The free-rider problem is an example of market failure.
Madeline listens to the radio station but she didn't contribute.
Opportunity cost is the cost of opportunity forgone.
Negative externality is when the cost of production or consumption activities exceeds its benefits to a third party.
Deadweight loss occurs when market equilibrium isn't achieved.