The change in the gravitational potential energy when a body mass m is raised to a height nR above the surface of the earth is

Q: The change in the gravitational potential energy when a body mass m is raised to a height nR above the surface of the earth is (here R is the radius of the earth)

(a) $(\frac{n}{n+1}) m g R$

(b) $(\frac{n}{n-1}) m g R$

(c) $n m g R$

(d) $\frac{m g R}{n}$