The important compounds in living things include

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.

it's not c. i took the quiz and got it wrong. so my best guess is b.

have a great day, and hope this .