A circular curve of a highway is designed for traffic moving at 72 km/h. if the radius of the curved path is 100 m, the correct angle of banking of the road should be given by:
A. `tan^(-1)((2)/(5))`
B. `tan^(-1)((3)/(5))`
C. `tan^(-1)((1)/(5))`
D. `tan^(-1)((1)/(4))`