# A car is moving on a circular level road of curvature $300\;m$. If the coefficient of friction is 0.3 and acceleration due to gravity $10\;m/s^2$, the maximum speed that car can have is :
( A ) $162\; km/h$
( B ) $30\;km/h$
( C ) $81\;km/h$
( D ) $108\;km/h$