MI about an axis passing through tangent to the ring: \(I=\frac{1}{2} MR ^2+ MR ^2=\)
\(\frac{3}{2} MR ^2\) by parallel axis theorem
For maximum radius of gyration ring should have maximum moment of inertia about a axis here, option \([D]\) has maximum moment of inertial which is \(2 MR ^2\)