Which of the Following Is an Example of the U

Which of the following is an example of the U.S. government's use of a "command and control" approach to reducing pollution?

A) In 1990, Congress approved measures designed to reduce sulfur dioxide emissions to 8.5 million tons annually by 2010.
B) The U.S. government imposed a tax on electric utilities to reduce damages from acid rain.
C) The government issued electric utilities tradable emissions allowances in order to reduce emissions of nitrogen oxide.
D) In the 1980s, the U.S. government required the installation of catalytic converters to reduce emissions from all new automobiles.