At What Angle Should the Roadway on a Curve with a 50m

Multiple Choice

At what angle should the roadway on a curve with a 50m radius be banked to allow cars to negotiate the curve at 12 m/s even if the roadway is icy (and the frictional force is zero) ?

A) 0°
B) 16°
C) 17°
D) 35°
E) 73°