What should a train operator do when stopping a local train at a home signal on an upgrade?

When stopping a local train at a home signal on an upgrade, keeping the full service brake applied is the appropriate action. This is because applying the full service brake ensures that the train is securely and safely stopped, especially on an incline where the risk of rolling back is present. It provides maximum braking force to counteract the force of gravity acting on the train, thus preventing any unintended movement.

In the context of train operations, especially on upgrades, the train operator needs to maintain control over the train's movement. Keeping the full service brake applied helps ensure that the train remains stationary against the slope until it is time to proceed. This is particularly crucial in maintaining safety and preventing accidents, as a train not properly secured can lead to dangerous situations.

The options that suggest releasing the brakes or reducing speed gradually do not adequately address the need for stopping completely and securely on an upgrade. Similarly, applying emergency brakes could create a jerky stop, which may not be safe or necessary in this situation. The correct action, therefore, focuses on stability and control, making the choice of keeping the full service brake applied the best practice.