A disc of mass M and radius R is rolling with angular speed w on a horizontal plane as shown. The magnitude of the angular momentum of the disc about the origin O is :

Question

 

$$\begin {array} {1 1} (a)\;(1/2) MR^2 w & \quad (b)\;MR^2w \\ (c)\;\frac{3}{2} MR^2 w & \quad  (d)\;2MR^2w \end {array}$$