Fact 1: Air pollution harms the respiratory and circulatory systems. Fact 2: Incinerated mercury pollutes the air. Given the two facts above, what harms the respiratory and circulatory systems?

Pick from:
A). Greenhouse gasses
B). burning coal
C). inoculation
D). incinerated mercury
E). fossil fuels
F). water vapor
G). Sulfur dioxide
H). air
Answer:
D).