An ecosystem's sustainability is most dependent on - A. the amount of water there.

B. warm temperatures

C. the number and variety of organisms that live there.

D. having a large number of a single plant species.​

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: