Which of the following statements about trade and domestic pollution is accurate?

a.Free trade is likely to cause producers to reduce their levels of pollution due to international competition.

b.It is possible for free trade to hurt a country if polluters are forced to internalize the external costs associated with their production.

c.In the presence of free trade, the costs of pollution can be transferred almost completely by the exporting country to the importing country.

d.If polluters are not forced to internalize the external costs associated with their production, free trade could result in the country exporting the wrong products.