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

1. A
   $\frac{l^2{\omega }^2}{32g}$
2. B
   $\frac{l\omega }{6g}$
3. C
   $\frac{l^2{\omega }^2}{2g}$
4. D
   $\frac{l^2{\omega }^2}{6g}$