A rocket of mass M is launched vertically from the surface of the earth with an initial speed V. Assuming the radius of the earth to be R and negligible air resistance, the maximum height attained by the rocket above the surface of the earth is 

• A

  $\mathrm{R}/\left(\frac{\mathrm{gR}}{2{\mathrm{V}}^2}-1\right)$

• B

  $\mathrm{R}\left(\frac{\mathrm{gR}}{2{\mathrm{V}}^2}-1\right)$

• C

  $\mathrm{R}/\left(\frac{2\mathrm{gR}}{{\mathrm{V}}^2}-1\right)$

• D

  $\mathrm{R}\left(\frac{2\mathrm{gR}}{{\mathrm{V}}^2}-1\right)$