When does HYD pump 1B activate in AUTO mode?

The activation of HYD pump 1B in AUTO mode is primarily linked to the operational status of any generator. When a generator is operating, it provides the necessary electrical power to the hydraulic systems on the aircraft, including the hydraulic pumps. This ensures that hydraulic pressure is available for various flight control surfaces and landing gear operations. Therefore, the correct choice reflects the direct relationship between generator operation and the activation of HYD pump 1B, as having power is essential for the pump to function and provide hydraulic pressure.

The other options, while related to hydraulic system operation, do not directly trigger the activation of HYD pump 1B in the AUTO mode. Flaps being greater than 0 may indicate that hydraulic power is needed, but it doesn't control the pump's activation by itself. Moreover, while sufficient hydraulic fluid levels are crucial for overall system functionality, they do not initiate the pump's operation. Similarly, the supply of AC power is important for the pump’s operation, yet it is the status of the generator specifically that confirms the availability of power which is a decisive factor for the pump's activation in AUTO mode.