What is a sign of a properly functioning parking brake?

Answer: B — It holds the vehicle stationary on an incline

A properly functioning parking brake is designed to hold the vehicle stationary, especially on inclines. This capability is essential for preventing the vehicle from rolling away when parked. The parking brake mechanism actively engages the rear wheels and provides a secure hold, which is crucial for safety. When a vehicle is parked on a slope, a functioning parking brake will maintain its position without the need for additional support or excessive force. This ability ensures that the vehicle does not move unintentionally, protecting both the vehicle itself and anyone nearby. Therefore, option B accurately identifies a key characteristic of the parking brake's functionality, emphasizing its importance in vehicle safety and control.