The correct answer is A) The system integrates propulsion and steering into one function. Azipod propulsion systems combine the propulsion and steering functions into a single unit. The propulsion unit, or pod, can rotate around a vertical axis, allowing it to provide both thrust and steering without the need for a separate rudder. This integrated design is one of the key features of Azipod systems, eliminating the need for additional steering components. The other answer choices are incorrect because: B) Azipod systems do not require a controllable-pitch propeller, C) they do not need a separate rudder, and D) the pod assembly rotates on a vertical axis, not a horizontal one.