If you could just answer this real quick that would be great! The carbon cycle involves a variety of processes that move and convert carbon between Earth systems. The diagram summarizes the main processes of the carbon cycle.

What best describes the role of human activities in the carbon cycle?

A. Human activities have little if any effect on the carbon cycle.
B. Human activities affect only one event of the carbon cycle, which is the burning of fossil fuels.
C. Human activities affect many events of the carbon cycle, including the burning of fossil fuels, but do not affect all events.
D. Human activities affect or alter all events of the carbon cycle.