At what departure angle should a body be projected so that the maximum vertical height attained by a projectile is equal to the horizontal range ?

Question

\[(a)\;\alpha=\tan ^{-1} 1/4 \quad (b)\;\alpha=\tan ^{-1} 1/2 \quad (c)\;\alpha=\tan ^{-1} 2 \quad (d)\;\alpha=\tan ^{-1} 4\]