What Has Been the Result for Air Quality from Strict

Multiple Choice

What has been the result for air quality from strict emission controls?

A) Strict emission controls have resulted in a dramatic improvement in air quality.
B) Strict emission controls are largely ignored thus air quality has dramatically decreased.
C) Strict emission controls have led industrialists to be contrite and to stop polluting.
D) The growth in use of automobiles/trucks has wiped out much of the gain from emission controls.