A rocket is launched vertical from the surface of the earth of radius R with an initial speed v. If atmospheric resistance is neglected, then maximum height attained by the rocket is

• A

  $h=\frac{R}{\left(\frac{2gR}{v^2}-1\right)}$

• B

  $h=\frac{R}{\left(\frac{2gR}{v^2}+1\right)}$

• C

  $h=\frac{R^2}{\left(\frac{2gR}{v^2}-1\right)}$

• D

  $h=\frac{R^2}{\left(\frac{2gR}{v^2}+1\right)}$