If you increase the mass of object-A (choice-A) OR object-B (choice-B), the gravitational force between them will increase. So naturally, if you increase the mass of both object A and object B, you'll get both increases. (D)
Increasing the distance between the objects (choice-C) will DEcrease the gravitational force between them. This is a big part of the reason why we never feel especially attracted toward Jupiter.
