Points on a Map to the Same Side of a Certain

Points on a map to the same side of a certain contour on a topographic map will all have

A) the same mineral composition,unless there is no index contour on the map.
B) elevations that are all above,or all below,the elevation that the contour represents.
C) rivers and streams that run parallel to the contour line,while points on the other side of that contour have rivers and streams that do not run parallel to the contour line.
D) more similar climate than points to the other side of that contour line.