Answer:
The correct answer is A. Acid rain and air pollution are major environmental concerns that are being addressed by new technology.
Explanation:
Acid rain is the phenomenon of unusually acidic meteorological precipitation, such as rain, hail, snow, fog, frost, and even dry dust. It occurs due to the presence in it of acidic dissolved pollutants, that is, substances (gaseous or not) which are not normal characteristics of the clean atmosphere, but are products of human activity or other pollutants. As various fossil fuels, such as petroleum and coal, exhaust gases that often contain acidic oxides of sulfur and nitrogen, among others, an acid rain is produced that dissolves the corresponding acids.
Acid rain has devastating effects that vary depending on the acidity, oxidation, concentration of toxic substances, the amount, duration and composition of the soil that falls into ecosystems, crops, cultural monuments and property of citizens. The severe effects of the phenomenon have forced, in recent years, many governments to impose laws and other measures in order to reduce, at least, the phenomenon and therefore its effects, as well as the implementation of different technologies to reduce its impact.