What kind of violation might prompt an officer to initiate contact with the driver?

The selection of "All of the above" is accurate because each scenario presented can independently serve as a valid reason for a law enforcement officer to initiate contact with a driver.

Failure to signal when changing lanes or making turns is a common traffic infraction that can lead to unsafe driving conditions. Officers are trained to recognize such violations, as they indicate negligent driving behavior that could potentially endanger not only the driver but also other road users.

Expired registration presents another clear reason for police intervention. Operating a vehicle with outdated registration is against the law, and officers have the responsibility to ensure that vehicles on the road are properly registered and compliant with state regulations.

Excessive speeding is also a significant violation that warrants officer contact. Driving well beyond the speed limit poses a major risk of accidents and can indicate reckless driving behaviors. Officers aim to address such behavior promptly to maintain road safety.

Since each of these actions can warrant police enforcement due to their impact on road safety and legal compliance, the correct answer encompasses all three violations.