Answer:
When the distance between the two objects is decreased by half, then Option B: The gravitational attraction increases 2x.
Explanation:
'Gravitational force' is always the reverse to the space between the two objects.
If the distance between the two objects increases, gravitational force decreases between them. On the other hand, using the given model if the distance between the two objects is decreased by half then the gravitational force is doubled. Thus, option B is the correct option which says that gravitational force will become 2 times. It will not increase 4 times as per option A. It will also not remain constant as per option C, neither it will decrease by 1/4 as per Option D.