Motion in a Plane question for NEET / JEE Main, with solution

Answer: (A) $30°$

$$\frac{R}{H} = \frac{2u^2\sin\theta\cos\theta/g}{u^2\sin^2\theta/2g} = 4\cot\theta$$
$$4\cot\theta = 4\sqrt{3} \;\Rightarrow\; \cot\theta = \sqrt{3} \;\Rightarrow\; \theta = 30°$$

Solution by Sreeraj P, M.Sc Physics