If the Production of a Product Results in Harmful Externalities

If the production of a product results in harmful externalities, then

A) private costs equal costs to society.
B) all costs are being borne by the producer of the product.
C) there is an overallocation of resources to the production of the product.
D) there is an underallocation of resources to the production of the product.
E) production of the product should be stopped.