Question

which of the following contributes the most to the reaction that produces secondary air pollution from a combination of primary pollutants?
altitude
pressure
sunlight
gravity

Explanation:

Secondary air pollution often results from photochemical reactions among primary pollutants. Sunlight provides the energy for these photochemical reactions to occur, playing a crucial role. Altitude, pressure, and gravity do not directly contribute as significantly to the chemical reactions that produce secondary air - pollution.

Answer:

sunlight