Answer:
D) F
Explanation:
Let m and M be the mass of the balls A and B respectively and r be the distance between the two balls. The magnitude of attractive gravitational force experienced by the balls due to each other is given by the relation :
[tex]F=\frac{GMm}{r^{2} }[/tex] Â Â Â ......(1)
Now, if the masses of both the balls gets doubled as well as there separation distance also gets doubled, then let Fâ be the new gravitational force acting on them.
Since, New mass of ball A = 2M
      New mass of ball b = 2m
Distance between the two balls = 2r
Substitute these values in equation (1).
[tex]F_{1} =\frac{G(2M)(2m)}{(2r)^{2} }[/tex]
[tex]F_{1} =\frac{4GMm}{4r^{2} }=\frac{GMm}{r^{2} }[/tex]
Using equation (1) in the above equation.
Fâ = F