A vehicle is moving with a velocity u on a curved road of width b and radius of curvature R. For counteracting the centrifugal force on the vehicle, the difference in elevation required in between the outer and inner edges of the road is

• A.  \[\frac{{{v}^{2}}b}{Rg}\]                               
• B.         \[\frac{vb}{Rg}\]
• C.  \[\frac{v{{b}^{2}}}{Rg}\]                             
• D.         \[\frac{vb}{{{R}^{2}}g}\]