Which of the following countries are most affected by Acid Rain? Choose the correct answer from the codes given below: (1) Canada (2) Norway (3) Sweden (4) United Kingdom

Acid rain occurs when chemical elements or pollutants in the atmosphere mix with moisture and fall as acidic rain. Canada, Sweden, and Norway are among the most affected countries by acid rain. These countries face high levels of environmental pollution, particularly due to industrial emissions. Other countries such as Finland, Netherlands, Germany, and Italy are also impacted by acid rain. In Asia, India and China are particularly vulnerable due to the large number of factories emitting pollutants. Thus, the correct answer is (d) 2, 3 and 4.