Let AB be the tower and BC be the shadow. Join A and C. We get a right-angled triangle right-angled at B. The angle of elevation of the sun is ∠ACB(θ, say). Given that, BC = √3AB. We will use trigonometric ratio tan for the triangle taking AB as height and BC as the base.

In ∆ABC,

or,

θ = 30°

since we know that tanθ is 1/√3 whenever θ = 30°.

So, the correct option is (B).