Correct Response: B. A vertical line extending from the North Pole to the South Pole and passing through England, Spain, and West Africa, the prime meridian represents zero degrees longitude. It is the starting point for measuring longitude east and west of the line, which is of vital importance for navigation and geo positioning. The prime meridian does not serve as a division line between the tropical and temperate climate zones (A) through which it passes. While the prime meridian, together with its opposite—the 180 degree meridian—is sometimes used to demarcate the Eastern and Western Hemispheres (C), that is not its major purpose, nor is the division of the two hemispheres consistently identified with the prime meridian. Although the prime meridian forms a portion of a great circle, it does not provide a starting point for the measurement of great circles (D).
