The Roosevelt Island Tramway in New York City Spans the East

The Roosevelt Island Tramway in New York City spans the East River and connects Roosevelt Island to Manhattan. It is the only commuter aerial tramway in North America. Between two particular points, the altitude change is 50 ft when the horizontal distance between them is 100 ft. The grade (the steepness) of this portion of the path is

A) 0.35.
B) 0.50.
C) 1.0.
D) 2.0.
E) 4.0.