Inelastic Collisions in One Dimension: in the Figure, Determine the Character

Inelastic collisions in one dimension: In the figure, determine the character of the collision. The masses of the blocks, and the velocities before and after are given. The collision is

A) perfectly elastic.
B) partially inelastic.
C) completely inelastic.
D) characterized by an increase in kinetic energy.
E) not possible because momentum is not conserved.