The maximum speed with which a car can be driven round a curve of radius 18 m without skidding (when $g = 10\;m/s^2$ and the coefficient of friction between rubber tyres and the roadway is $0.2$ ) is :

Question

( A ) $18.0 \; km/h$
( B ) $36.0 km/h$
( C ) $14.4\; km/h$
( D ) $21.6 \; km/h$