Three rings each of mass M and radius R are arranged as shown. The moment of inertia of the system about $YY'$ will be

Question

 

\[\begin {array} {1 1} (a)\;3\;MR^2 & \quad (b)\;\frac{3}{2}\;MR^2 \\ (c)\;5\;MR^2 & \quad  (d)\;\frac{7}{2} MR^2 \end {array}\]