A source on a swing which is covering an angle θ from the vertical is producing a frequency v. The source is distant d from the place of support of swing. If velocity of sound is c, acceleration due to gravity is g, then the maximum and minimum frequency heard by a listener in front of swing is  

(A) $\frac{\mathrm{cv}}{\sqrt{2\mathrm{gd}-\mathrm{c}}},\frac{\mathrm{cv}}{\sqrt{2\mathrm{gd}+\mathrm{c}}}$
(B) $\frac{\mathrm{cv}}{\sqrt{2\mathrm{gd} \left(1-\mathrm{cos\theta }\right)}-\mathrm{c}},\frac{\mathrm{cv}}{\sqrt{2\mathrm{gd} \left(1-\mathrm{cos\theta }\right)}+\mathrm{c}}$
(C) $\frac{\mathrm{cv}}{\mathrm{c}-\sqrt{2\mathrm{gd} \left(1-\mathrm{cos\theta }\right)} },\frac{\mathrm{cv}}{\mathrm{c}+\sqrt{2\mathrm{gd} \left(1-\mathrm{cos\theta }\right)}}$
(D) $\frac{\mathrm{cv}}{\mathrm{c}-\sqrt{2\mathrm{gd} \left(1-\mathrm{sin\theta }\right)} },\frac{\mathrm{cv}}{\mathrm{c}+\sqrt{2\mathrm{gd} \left(1-\mathrm{sin\theta }\right)}}$