A gramphone record is revolving with an angular velocity `omega`. A coin is placed at a distance `R` from the centre of the record. The static coefficient of friction is `mu`. The coin will revolve with the record if
A. `r= mu g omega^(2)`
B. `r lt omega^(2)/(mu g)`
C. `r le (mu g)/omega^(2)`
D. `r ge (mu g)/omega^(2)`
