A comet is moving in a highly elliptical orbit round the sun. When it is closest to the sun, its distance from the sun is r and its speed is v. When it is farthest from the sun, its distance from the sun is R and its speed will be

• A

  $\mathrm{v}{\left(\frac{\mathrm{r}}{\mathrm{R}}\right)}^{1/2}$

• B

  $\mathrm{v}\left(\frac{\mathrm{r}}{\mathrm{R}}\right)$

• C

  $\mathrm{v}{\left(\frac{\mathrm{r}}{\mathrm{R}}\right)}^{3/2}$

• D

  $\mathrm{v}{\left(\frac{\mathrm{r}}{\mathrm{R}}\right)}^2$