A magnetic needle of magnetic moment $6.7 \times 10^{-2} \; Am^2$ and moment of inertia $7.5 \times 10^{-6} kg\;m^2$ is performing simple harmonic oscillations in a magnetic field of $0.001\; T$. Time taken for $10$ complete oscillations is :

Question

( A ) 6.98 s
( B ) 6.65 s
( C ) 8.89 s
( D ) 8.76 s