What action should a driver take when they experience brake failure while driving?

Answer: A — Apply the parking brake gradually

When a driver experiences brake failure while driving, applying the parking brake gradually is the recommended action. This method allows the driver to slow down the vehicle safely without causing a sudden stop that could lead to losing control. The parking brake operates independently from the main brakes, and by applying it gradually, the driver can decelerate the vehicle while maintaining steering control. Other actions, such as shifting into neutral immediately, may lead to complications because it can reduce control over the vehicle's speed and steering, potentially causing skidding. Stopping the vehicle suddenly can result in loss of traction or control, especially if the road conditions are poor. Accelerating to gain more control is counterproductive, as it could exacerbate the situation by increasing speed when the driver is trying to stop or slow down.