Electricity which may efficient transportation if you develop your way depending contact metal basis , such as electric train .
-Water is from of heat-energy using solar power which run a turbine may be wheel on a railway path.
The gravitational force between two object depends on their masses and on their distance.
Since the formula is

If the masses grow, the force also grows. But I'm assuming the two objects are fixed, so you can't enlarge their mass.
So, the only option remaining is to lower their distance: since it sits at the denominator, a smaller value of d results in a bigger value for F.
So, if you reduce the distance between two objects, the gravitational force between them will always result in an increase
If F = Gm₁m₂/d², and we change m₁ to 5m₁ and m₂ to 2m₂, then the new magnitude of the gravitational force is
F' = G (5m₁) (2m₂) / d²
F' = 10 Gm₁m₂ / d²
but this is really just F' = 10F. So J is the correct choice.