<span>The correct answer is B. Pulmonary. The answers C. Cerebral and D. Extremity, are baseless regarding this question; A. Systemic could be a good alternative, as the blood flows from the systemic to the pulmonary circulation in the right side of the heart; but the systemic circulation is in fact mostly handled in the left side of the heart, while the right side handles the pulmonary one. </span>
The primary source of energy that drives convection within the atmosphere and oceans is the sun.
I believe the answer is littoral zones.
Sorry if I'm wrong, Hope this helps.
