What action should a train operator take to cut out the brakes on a car?

To cut out the brakes on a car, the appropriate action is to pull up the brake cylinder cut-out cock. This mechanism allows the train operator to disengage the braking system of a specific car, thereby preventing it from applying brakes.

This procedure is often necessary in certain situations, such as when a car needs to be moved independently or during maintenance checks. The brake cylinder cut-out cock is specifically designed for this purpose, making it the correct and safe choice.

Other options, while related to train operation, serve different functions. For instance, pushing the emergency brake button would engage braking force across the whole train, which is not suitable when the intention is to cut out brakes on a specific car. Turning off the master controller would cease all propulsion and control functions of the train, rather than addressing the braking system of an individual car. Releasing the brake handle generally applies the brakes to the car, which is counterproductive to the goal of cutting them out. Thus, using the brake cylinder cut-out cock is the correct and intended method for this operation.