What is the primary purpose of the wing tank pumps during normal operations?

The primary purpose of the wing tank pumps during normal operations is to feed the engines first. This function is crucial because the engines require a steady and reliable supply of fuel to operate efficiently and safely. In the A320, fuel is primarily used from the wing tanks when the aircraft is flying, particularly during initial climb and cruise phases, as it ensures the engines receive the necessary fuel to maintain optimal performance.

While the other options outline some secondary functions that the wing tank pumps may fulfill, they are not the main purpose during standard conditions. For instance, backup for the center tank pumps is a valid function, but it is not what the wing pumps are primarily designed to do during typical operation. Similarly, providing fuel for recirculation and transferring fuel to the center tank are actions that can occur under specific circumstances but do not reflect the primary operational intent of the wing tank pumps. Feeding the engines remains the paramount reason for their design and operation in flight.