$A$ solid body rotates about a fixed axis such that its angular velocity depends on $\theta$ as $\omega = k \theta^{-1}$,where $k$ is a positive constant. At $t = 0$,$\theta = 0$. Then,the time dependence of $\theta$ is given as ..........

• A
  $\theta = k t$
• B
  $\theta = 2 k t$
• C
  $\theta = \sqrt{k t}$
• D
  $\theta = \sqrt{2 k t}$