What must be done to resume normal operations after being in Release mode?

To resume normal operations after being in Release mode, obtaining permission from the Trainmaster is crucial. This process ensures that all necessary safety checks and communication protocols are adhered to before the train returns to its regular operational status. The Trainmaster is responsible for monitoring the overall safety and efficiency of train operations, and their approval is a critical step in preventing accidents or operational misunderstandings.

Other actions mentioned, such as automatically resuming operations when 'CBTC Available' is shown, or waiting for a specific duration, may not encompass the necessary checks and authorizations needed to ensure safety. Similarly, initiating emergency protocols could imply a situation that requires intervention rather than a simple resumption. Therefore, effective chain-of-command communication is vital, making permission from the Trainmaster the correct procedure for a safe transition back to normal operations.