Disc A has moment of inertia $I$ and angular velocity $\omega$. Disc B has moment of inertia $2I$ and is initially at rest. When disc B is brought in contact with disc A, they acquire a common angular velocity in time $t$. The average frictional torque on one disc by the other during this period is\\
(A) $\frac{2I\omega}{3t}$\\
(B) $\frac{9I\omega}{2t}$\\
(C) $\frac{9I\omega}{4t}$\\
(D) $\frac{3I\omega}{2t}$