The frequency of oscillation of a torsional pendulum is

• A. <img src="/_files/images/mechanical-engineering/theory-of-machines/478-94-1.png">
• B. <img src="/_files/images/mechanical-engineering/theory-of-machines/478-94-2.png">
• C. <img src="/_files/images/mechanical-engineering/theory-of-machines/478-94-3.png">
• D. <img src="/_files/images/mechanical-engineering/theory-of-machines/478-94-4.png">