Drumlins Are Smooth, Elliptical Shaped Mounds of Till

Drumlins are smooth, elliptical shaped mounds of till. How do they help us determine the directional flow of continental ice sheets?

A) the long axis of the elliptical-shaped drumlin is parallel to the directional flow
B) the long axis of the elliptical-shaped drumlin is perpendicular to the directional flow
C) two or more drumlins will make an arrow shape that points in the direction of flow
D) there is no way to determine the flow of past continental ice sheets by looking at drumlins