If Air Pollution Control Is a Public Good, It Follows

If air pollution control is a public good, it follows that:

A) the efficient output of air pollution control is zero.
B) additional persons can benefit from a given amount of air pollution control without reducing the benefits enjoyed by others.
C) the efficient output of air pollution control can be attained by selling it by the unit in a market.
D) the more air pollution control enjoyed by any one person, the less is available to others.