The moment of inertia of a sphere of mass M and radius R about an axis passing through centre is $\large\frac{2}{5}\;$$MR^2$. The radius of gyration of the sphere about a parallel axis to the sphere is

Question

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