If a fly wheel makes 120 revolutions per minute then its angular speed will be

Question

$$\begin {array} {1 1} (a)\;8 \pi \;rad/s & \quad (b)\;6 \pi \;rad/s \\ (c)\;4 \pi\; rad/s & \quad  (d)\;2 \pi \;rad/s \end {array}$$