i do not think your answer is correct
as T = 2.pi. Sqrt( 2.L / 3.g) so and angular frequency w = 2.pi / T so option b seems to be correct you can see hyperphysics site or
is not it the case similar to simple pendulum and time period for simple pendulum is T=2.pi sqrt(L/g) ?
Bar pendulum is not similar to a simple pendlum as the masses are spread in a particular manner and it leads to moment of Inertia as it oscillates where as in simple pendulum mass is concentrated at a point at length L.
if you have analysed a compound pendulum or a rigid body hung from a point and oscillating then the picture of restoring torque and angular acceleration will be clear.....see the reference of mit given above for detail. or consult a text book dealing with oscillation of a rigid body from a fixed axis.
its clear now Thanks a globe
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