The correct answer is A. Photochemical smog.
Photochemical smog is a type of air pollution that is formed when sunlight reacts with chemicals released into the air from cars, power plants, and other sources. It is a major problem in many urban areas, and can cause a variety of health problems, including respiratory problems, heart disease, and cancer.
Dust particles are small pieces of solid matter that are suspended in the air. They can come from a variety of sources, including soil,
rocks, and plants. Dust particles can cause a variety of health problems, including respiratory problems, heart disease, and cancer.Sulfur dioxide (SO2) is a gas that is released into the air from burning fossil fuels, such as coal and oil. It can cause a variety of health problems, including respiratory problems, heart disease, and cancer.
Nitrogen dioxide (NO2) is a gas that is released into the air from burning fossil fuels, such as coal and oil. It can cause a variety of health problems, including respiratory problems, heart disease, and cancer.
Photochemical smog is a secondary air pollutant because it is formed when primary air pollutants, such as NO2 and SO2, react with sunlight. Primary air pollutants are released directly into the air from sources, such as cars and power plants.