A silent killer is spreading poison across the earth. Rain, polluted by the gases given off by factories and motor vehicles, is becoming highly acidic. This "acid rain" is slowly destroying our environment. Acid rain has already damaged millions of acres of forests. It runs off into waterways, polluting drinking water and killing plant and animal life. Acid rain also has a harmful effect on the human body, causing lung disease and other health problems. Even our structures are affected, because acid rain eats away at buildings and monuments. Acid rain has proved to be difficult to control, so government officials have hesitated to do anything about it. This cannot go on. We must urge our representatives to pass stronger antipollution laws with stiff punishment if they are not obeyed. We must act now before it is too late. Use the passage to answer the question. What is the primary purpose of this selection? A. to inform lawmakers about acid rain B. to persuade readers to take action against acid rain C. to explain where acid rain comes from D. to describe the effects of acid rain on the human body