In an experiment, a spring is placed between object X and object Y. Object X has twice the mass of object Y, which has mass M. The two objects are pushed together until the spring is at its maximum compression, as shown in the figure. The objects are released from rest; and data are collected for the speed of each object immediately after the spring is no longer compressed. However, the graph does not indicate which object corresponds to a given velocity, and the positive direction is not indicated. Which of the following correctly describes the velocities of object X and object Y after the collision?