<span>3) Oceans
The oceans are a massive carbon sink, and part of the positive reinforcement of the greenhouse gas cycle is that, as the oceans become warmer, then tend to release more carbon dioxide dissolved in the water which in turn drives temperatures warmer.</span>
A is the correct answer to the question
Secondary since plants/animals already lived there, but got killed/driven out of the area they lived/thrived in/on.
