With slats retracted, how is fuel sequenced to the engines when there is fuel in all tanks?

When slats are retracted and there is fuel in all tanks, the correct sequence for fueling the engines involves the center tank pumps feeding the engines first. This is designed to optimize fuel distribution and balance in the aircraft. The A320 has a fuel system that prioritizes the usage of the center tank fuel before the wing tanks, primarily to ensure that the aircraft's center of gravity remains within optimal limits as fuel is consumed.

This sequence helps in maintaining proper aerodynamic performance and handling characteristics during flight. Once the center tank is sufficiently depleted, the system transitions to utilize the wing tank fuel, ensuring that the overall fuel management is efficient throughout the flight. The other options suggest varying methods of fuel feeding that either lack this prioritization or imply simultaneous use, which does not match the operational design of the aircraft’s fuel system under these conditions.