If the HYD 1B pump is in AUTO and the left engine is OFF, under what conditions will the 1B pump come on?

The correct choice is based on the operational logic of the hydraulic system in aircraft. When the HYD 1B pump is set to AUTO, it activates automatically under certain conditions to ensure proper hydraulic system functionality, particularly when the left engine is not operating.

In this scenario, when the left engine is OFF, the system relies on factors such as flap position and AC generator status to determine if hydraulic pump activation is necessary.

When the flaps are set to greater than 0, it indicates that the aircraft is likely in a configuration that requires additional hydraulic power for the operation of flight controls and landing gear. If the AC generator is also ON, it confirms that there is sufficient electrical power available to run the pump, enabling it to activate as needed to provide hydraulic pressure for these operations.

This interaction between flap position and AC generator status is crucial for ensuring that the hydraulic system can respond adequately in flight configurations that may require increased hydraulic support, thereby maintaining aircraft safety and performance.