There is a circular tube in a vertical plane. Two liquids which do not mix and of densities $d_{1}$ and $d_{2}$ are filled in the tube. Each liquid subtends $90^{\circ}$ angle at the centre. Radius joining their interface makes an angle $\alpha$ with vertical plane. Ratio $\frac{d_{1}}{d_{2}}$ is [2014](A) $\frac{1+\sin \alpha}{1-\sin \alpha}$
(B) $\frac{1+\cos \alpha}{1-\cos \alpha}$
(C) $\frac{1+\tan \alpha}{1-\tan \alpha}$
(D) $\frac{1+\sin \alpha}{1-\cos \alpha}$