If the distance between two masses is doubled, the gravitational attraction between them

We know that according to the law of gravitation, the gravitational force between any two bodies that have some mass is given as:

${\text{F}}_{ }=\text{G}.\frac{{\text{Mm}}_{ }}{R_{ }^2}$
Where M and m are the masses of the two bodies, R is the distance between them and G is the universal gravitation constant.

In the given question, 

$\text{R}=2\text{R}$

Substituting the value,

$\text{F}=\frac{\text{GMm}}{{\left(\text{2R}\right)}^{\text{2}}}$

$\text{F}=\frac{\text{GMm}}{{\text{4R}}^{\text{2}}}$

Force will reduce to a quarter.

Therefore, option D is the correct answer.