A planet moving along an elliptical orbit is closest to the sun at a distance $r_1$ and farthest away at a distance of $r_2$. If $v_1$ and $v_2$ are the linear velocities at these points respectively, then the ratio $\frac{v_1}{v_2}$ is :

Question

( A ) $r_2/r_1$
( B ) $(r_2 / r_1)^2$
( C ) $(r_1/r_2)^2$
( D ) $r_1 / r_2$