"A number of cities and states have banned smoking in bars because of secondhand smoke. In cities without the ban, the bar owners decides whether smoking is permitted. If smokers have a greater willingness to pay to smoke than nonsmokers have to avoid smoke, then bar owners will ___ smoking, which is an ___ outcome.
A - permit ; inefficient (NOT this one)
B - ban ; efficient
C - ban ; inefficient
D - permit ; efficient"