What is the purpose of the parking brake indicator?

Answer: C — Alerts the engineer when the parking brake is engaged

The purpose of the parking brake indicator is to alert the engineer when the parking brake is engaged. This indicator serves a critical function by providing a visual confirmation that the parking brake is applied, ensuring safety prior to departure. When the parking brake is engaged, it is essential for the engineer to be aware, as this could prevent accidental movement of the train while it is stationary. The parking brake indicator is a safety feature designed to minimize the risk of an unintended release and ensures that proper procedures are followed before starting the train's operation. Understanding the significance of this indicator is crucial for maintaining safe and efficient train operations.