The radius of gyration of a sphere of mass $M$ and radius $R$ about the axis parallel to the axis passing through its centre and tangent to the sphere is :

Question

( A ) $(\frac{\sqrt{3}}{5})R$
( B ) $\frac{7}{5}R$
( C ) $(\frac{\sqrt{7}}{5})R$
( D ) $\frac{3}{5}R$