To have gravitational force act between two objects, they must possess mass.
Explanation:
1. Gravitational force is a force of attraction between two objects with mass.
2. The greater the mass of the objects, the stronger the gravitational force between them.
3. Mass is a measure of the amount of matter in an object. Objects with mass are affected by gravity, which causes the gravitational force between them.
Therefore, for gravitational force to act on two objects, they must have mass. This is a fundamental requirement for the gravitational interaction to occur.
