Why didn't the state and local air pollution laws achieve the end of reducing pollution
A．Industries tend to disregard the laws because they don't want to spend extra money on the processing of industrial wastes.
B．Although measures are taken to send industrial pollutants higher up the atmosphere, the amount of industrial pollutants remains the same.
C．The smokestacks built to release pollutants are not tall enough.
D．Only a small number of industries are equipped to live up to the new standards of the air pollution laws.