The correct answer is A. acid rain.
Burning of coal produces oxides of sulphur and nitrogen, which combined with water vapor in the atmosphere, form sulfuric acid and nitric acid. These acids then fall to the Earth as acid rain, which can damage forests, lakes, and other ecosystems.
Brackish water is a mixture of salt water and fresh water. It is found in estuaries, lagoons, and other coastal areas. Brackish water is not suitable for drinking or irrigation, but it can be used for some industrial purposes.
Forest fires are caused by a variety of factors, including lightning strikes, human activity, and dry weather conditions. Forest fires can damage or destroy forests, and they can also release harmful pollutants into the atmosphere.
Soil pollution is caused by a variety of factors, including industrial waste, agricultural runoff, and mining activities. Soil pollution can make land unusable for agriculture or other purposes, and it can also pose a health risk to humans and animals.