The Emissions Trading Scheme Is Preferred by Economists Because

The emissions trading scheme is preferred by economists because:

A) clean air is not like any other scarce resource and cannot be traded on the market.
B) it treats the clean air as a limited economic resource which is owned by consumers and firms have to pay to use it.
C) once the trading scheme is in place, the firms have no control over how to minimise their losses.
D) it is up to the firms to decide on how much emissions they can produce.