If the masses of objects increase and their distance from each other remains the same, then the force of gravity between the two objects a) decreases. b) increases. c) remains the same. d) increases then decreases.

The force of gravity is that amount of attractive force which is exerted between two bodies on each other.

As per Newton's law of gravitation the force of gravity is directly  proportional to the product of the masses of the two bodies  and inversely proportional to the square of separation distance between them.

Mathematically

Here G is the gravitational constant whose value is 6.67×

As per the question the masses of the objects are increased keeping the separation distance same.

As force of gravity ∝ product of masses of two bodies,

Hence the force of gravity  increases with the increase of mass.