What action should be taken if you're experiencing brake failure?

Answer: B — Use your emergency brake gently

In the event of brake failure, using the emergency brake gently is the most effective course of action. The emergency brake, also known as the parking brake, is designed to engage the vehicle's rear brakes and help slow down the vehicle when the main braking system is compromised. It is important to apply the emergency brake gently to prevent causing the vehicle to skid or lose control, as a sudden application can lock the wheels. This method allows for a controlled decrease in speed, providing the driver with the opportunity to maneuver the vehicle to a safe location or stop it safely. It is critical to stay calm and manage the situation without causing further risk to yourself or others on the road.