When a train operator finds a male customer asleep on a train he just laid up, what is the best action to take?

When a train operator finds a male customer asleep on a train that has just been laid up, the best action is to stay with the customer and signal for assistance. This approach is appropriate because it ensures the customer's safety and well-being while also adhering to the operator's duty of care.

By remaining with the customer, the operator can monitor the situation and ensure that the individual is not in any distress or danger. Signaling for assistance helps to bring in additional resources, such as security or other staff trained to handle such situations, which can ensure the customer receives appropriate attention. This is especially important if the customer has medical needs or if there are safety concerns about leaving them unattended.

The other options may not provide the same level of care or responsibility. Leaving the customer alone could lead to potential risks, such as the customer waking up in an unfamiliar location or being in an unsafe environment. Waking the customer and instructing him to exit might not consider the individual's state of mind or physical condition, which could lead to confusion or a lack of proper support. Continuing with other duties neglects the responsibility of ensuring the safety of all passengers on the train. Therefore, staying with the customer while signaling for assistance is the best course of action.