Two bodies in space start moving towards each other, due to the gravitational force between them. Which of the following is true for these two bodies, assuming there are no other forces acting on them?

The correct options are
A The total energy is constant throughout this process
C Internal energy decreases with time
D The total kinetic energy increases with time
The gravitational potential energy of these two bodies, which is an internal energy gets converted into the kinetic energy. So, as time proceeds, KE increases and internal energy decreases