When an External Cost Associated with the Production of Some

When an external cost associated with the production of some good has been internalized,it means that

A) the opportunity cost of production is passed on to the consumer.
B) the private cost of production is borne by the producer.
C) the external costs are incorporated into private decision making.
D) the consumer is bearing the net social benefits imposed by the producer.
E) the firm is ignoring social costs.