A uniform rod of length l and mass m is swinging freely about a horizontal axis passing through its end.Its maximum angular speed is ω. Its centre of mass rises to a maximum height of

A. (1/6)(lω/g)
B. (1/2) (l²ω²/g)
C. (1/6) (l²ω²/g)
D. (1/3) (l²ω²/g)