When the negatively charged balloon is brought near the left can, the negatively charged electrons in the left can will be repelled by the negative charge of the balloon. This causes the electrons to move away from the balloon, resulting in a slight positive charge on the side of the can that is closest to the balloon and a slight negative charge on the side that is furthest away.
Since the two cans are touching, the effects of the electric field will influence both cans. The repulsion of electrons in the left can will cause them to move toward the right can, effectively transferring some of the negative charge to the right can.
Therefore, the correct response is:
From the left to the right of the cans.