To determine whether either object has a constant velocity, we would need information about their positions over time, their speeds, and directions of motion. Constant velocity means that both the speed and direction of the object remain unchanged.
Without specific details about objects C and D—such as their movements or a graph showing their positions over time—it's impossible to accurately assess their velocities.
If you can provide more context or details about the movements of objects C and D, I would be able to help you determine whether either has a constant velocity.