Which one of the following is a major environmental issue in eastern

Which one of the following is a major environmental issue in eastern Canada?

Acid precipitation
Groundwater depletion
Land degradation
Desertification
This question was previously asked in
UPSC NDA-2 – 2020
Acid precipitation (acid rain) has been a historically significant environmental issue in eastern Canada. Due to its geographical location downwind from major industrial areas in the Midwestern United States and central Canada, eastern Canada receives atmospheric pollutants, primarily sulfur dioxide and nitrogen oxides, which lead to the acidification of lakes, damage to forests, and degradation of infrastructure.
Eastern Canada is particularly vulnerable to transboundary air pollution leading to acid rain due to prevailing wind patterns and proximity to industrial regions.
While groundwater depletion and land degradation can be local or regional issues, and desertification is irrelevant to eastern Canada’s climate, acid precipitation was identified as a major widespread environmental problem in the region starting in the late 20th century, prompting significant domestic and international efforts to reduce emissions (e.g., Canada-US Acid Rain Accord).