Let's think step by step! What systems are pollutants bad for?
Options:
- (A) destroying life
- (B) classification system
- (C) an organism's body
- (D) respiratory and circulatory
- (E) animal habitats
- (F) ambulatory systems
- (G) social security system
- (H) the environment
The thinking starts now:
Air pollution harms the respiratory and circulatory systems. Air pollution is caused by lots of different pollutants. Several different pollutants harm the respiratory and circulatory systems. The final answer: (D).