The primary objective of the Clean Air Act is to protect what?

• A. The earth's biosphere
• B. The earth's stratosphere
• C. The atmosphere
• D. The ground water

Answer: (B)

The primary objective of the Clean Air Act is to protect the atmosphere. This federal law was enacted to control air pollution on a national level, aiming to ensure that air quality standards are established and maintained to safeguard public health and the environment. It addresses the emissions of hazardous air pollutants, criteria pollutants, and ozone-depleting substances, among other concerns related to the quality of air we breathe.

While the other options refer to important aspects of the environment, the Clean Air Act specifically targets air quality, making the atmosphere the correct focus of its protective measures. The biosphere and groundwater are significant components of the ecosystem, but they are not the direct subject of the legislation aimed at regulating air pollutants and ensuring clean air standards.