Choose the correct answer of the following question:

Let AB be the rod and BC be its shadow; and θθ be the angle of elevation of the sun.

We have,

$\mathrm{AB}: \mathrm{BC}=1: \sqrt{3}$

Let $\mathrm{AB}=x$

Then, $\mathrm{BC}=x \sqrt{3}$

In $\triangle \mathrm{ABC}$,

$\tan \theta=\frac{\mathrm{AB}}{\mathrm{BC}}$

$\Rightarrow \tan \theta=\frac{x}{x \sqrt{3}}$

$\Rightarrow \tan \theta=\frac{1}{\sqrt{3}}$

$\Rightarrow \tan \theta=\tan 30^{\circ}$

$\therefore \theta=30^{\circ}$

Hence, the correct answer is option (a).