The correct answer is: A. Fossil fuel
Ozone is a gas that is found in two layers in the Earth’s atmosphere. The ozone layer, which is located in the stratosphere, protects the Earth from harmful ultraviolet radiation. Ground-level ozone, on the other hand, is a major air pollutant that can cause respiratory problems, heart disease, and cancer.
Ground-level ozone is formed when sunlight reacts with certain chemicals in the air, such as nitrogen oxides and volatile organic compounds (VOCs). These chemicals are released into the air from a variety of sources, including cars, trucks, power plants, and industrial facilities.
Fossil fuels, such as coal, oil, and natural gas, are the primary source of nitrogen oxides and VOCs. When these fuels are burned, they release these chemicals into the air. In addition, fossil fuels can also release other pollutants, such as sulfur dioxide and particulate matter, which can contribute to the formation of ground-level ozone.
CFCs, or chlorofluorocarbons, are a type of chemical that was once widely used in refrigerators, air conditioners, and other products. However, CFCs are also very effective at destroying ozone in the stratosphere. As a result, the production and use of CFCs was banned in 1996 under the Montreal Protocol.
Oxygen is a gas that is essential for life. It is found in the air that we breathe and in the water that we drink. However, oxygen can also react with other chemicals to form ground-level ozone. This reaction is most likely to occur in areas with high levels of air pollution, such as cities and industrial areas.
Methane is a gas that is released from a variety of sources, including natural gas production, landfills, and agriculture. Methane is also a greenhouse gas, which means that it contributes to climate change. However, methane does not play a significant role in the formation of ground-level ozone.
In conclusion, the correct answer to the question “The ozone at ground level is primarily from ____ precursors” is A. Fossil fuel. Fossil fuels are the primary source of nitrogen oxides and VOCs, which are the chemicals that react with sunlight to form ground-level ozone.