A car of mass  $$m$$ moves on a banked road having radius  $$' r '$$ and banking angle  $$\theta.$$ To avoid slipping from the banked road, the maximum permissible speed of the car is  $$v_0.$$  The coefficient of friction $$\mu$$ between the wheels of the car and the banked road is:

A

$$\mu=\frac{v_0^2+rg\tan\theta}{rg-v_0^2\tan\theta} $$

B

$$ \mu=\frac{v_0^2-rg\tan\theta}{rg-v_0^2\tan\theta} $$

C

$$ \mu=\frac{v_0^2-rg\tan\theta}{rg+v_0^2\tan\theta} $$

D

$$\mu=\frac{v_0^2+rg\tan\theta}{rg-v_0^2\tan\theta}$$