Question

a grass snake living in northern england dies of natural causes. after a long period of time, its remains decay in the soil to become fossil fuel. when the fossil fuel is processed, sold and burned by humans, it releases carbon dioxide into the air. which aspect of this scenario shows a carbon source becoming a carbon sink?
o a. burning of the fossil fuel
o b. decaying of the snakes remains
o c. dead snake fossilizing underground
o d. respiration by the snake and humans
o e. humans processing and selling the fuel

Explanation:

A carbon source is something that releases carbon into the atmosphere. Burning fossil fuel releases carbon dioxide (a form of carbon) into the air. Decaying of snake's remains (B) and dead snake fossilizing underground (C) store carbon (more like carbon sinks in the long - term as the carbon is sequestered). Respiration by snake and human (D) is a natural process but in this context, the key is the fossil fuel burning. Humans processing and selling the fuel (E) doesn't release carbon, burning (A) does.

Answer:

A. burning of the fossil fuel