An Externality Is Internalized

An externality is internalized

A) when the person(s) or group that generated the externality incorporate into their own private cost-benefit calculations the external benefits (in the case of a positive externality) or the external costs (in the case of a negative externality) that third parties bear.
B) when people are made aware of it and realize that social benefits are less than private benefits (in the case of a positive externality) and that social costs are less than private costs (in the case of a negative externality) .
C) when the person(s) or group that generated the externality do not incorporate into their own private cost-benefit calculations the external benefits (in the case of a positive externality) or the external costs (in the case of a negative externality) that third parties bear.
D) it creates negative spillovers to society.