Final answer:
The greatest gravitational force occurs when both objects have large masses and are in close proximity to each other, per the formula for gravitational attraction which depends on both mass and distance.
Step-by-step explanation:
The forces of gravity between two objects will be the greatest when the masses of both objects are large and the objects are close together. This is because the gravitational force (Fgravity) is directly proportional to the product of their masses (M1 and M2) and inversely proportional to the square of the distance (R) between them, as described by the equation Fgravity = G M1 M2 / R2, where G is the gravitational constant. Therefore, the correct answer is A) when the masses of both objects are large and the objects are close together.