Two equal point masses are separated by a distance `d_1`. The force of gravitation acting between them is `F_1`. If the separation is decreased to `d_2`, then the new force of gravitation `F_2` , is given by
Options:
(a) `F_2=F_1`
(b) `F_2=F_1(d_1/d_2)^2`
(c) `F_2=F_1(d_2/d_1)^2`
(d) `F_2=F_1(d_1/d_2)`