If the paper clips W and X were the only ones that moved toward the magnet, and W is 1 centimeter away while X is 4 centimeters away, it indicates that the magnet effectively attracted paper clips within that range. Since these are the only paper clips that reacted to the magnet, we can conclude that the magnet does not work well for paper clips that are more than 4 centimeters away.
Therefore, the correct response is: 4 centimeters away.