What is one primary function of the Control Segment in GPS?

The primary function of the Control Segment in GPS is to monitor and control satellite signals. This segment comprises a network of ground stations that track the satellites, ensuring their orbits are accurate and that the satellite clocks are synchronized. These ground stations collect satellite data, determine any necessary adjustments to the satellite's trajectory, and update the satellites as needed. By monitoring the health and status of the satellites, the Control Segment maintains the overall integrity and accuracy of the GPS system.

The other options do not accurately describe the specific roles of the Control Segment. Providing user data pertains more to the satellite and user equipment functions, relaying signals to satellites does not align with the Control Segment's responsibilities, and storing satellite trajectory data is part of the function of the satellites themselves rather than the Control Segment.