Acid deposition would most likely result in

Acid rain.

Explanation:

According to some experts, acid precipitation can lead to acid rain. Acid rain is a product of chemical reactions caused by the release of compounds such as sulfur dioxide and nitrogen oxides into the air. These substances can form in the atmosphere itself and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

There are specific theories that nitrogen oxides cause acid rain, in other sulfur oxides, which are produced by the combustion of coal or petroleum products, for example, in thermal power plants, automobile engines, and plants for the production and purification of metals. With water vapor, they produce nitric or sulfuric acid, respectively. This natural disaster is very bad for flora and fauna, it has a particular negative reflection on forests and the aquatic world, especially fish.