Which Statement Is TRUE with Regards to the Use of Tradable

Which statement is TRUE with regards to the use of tradable permits for controlling carbon emissions?

A) Firms with lower costs of pollution abatement will demand more tradable permits.
B) The total amount of pollution would rise above the established cap if permit prices were set too high.
C) Environmental groups that purchase tradable permits and do not use them will push the price of remaining permits lower.
D) Advancements in abatement technology will lead to a decline in the price of tradable permits.