At what height from the surface of earth the gravitation potential and the value of $g$ are $– 5.4 \times 10^7 \;J \;kg^{–2}$ and $6.0\; ms^{–2}$ respectively ? Take the radius of earth as $6400\; km$ :

Question

( A ) 1400 km
( B ) 1600 km
( C ) 2000 km
( D ) 2600 km