Answer:
In an inelastic collision the kinetic energy is not conserved, but the total momentum of the system is conserved.
In other words; the Initial momentum
is equal to the Final Momentum
:

Then:
This means that after the collision the kinetic energy is transformed (dissipated) into another type of energy (caloric energy, for example); and there may be deformation in the blocks.
Therefore, the sentence that best describes this situation is:
The total momentum is zero.