What component provides hydraulic fluid for power steering?

The rotary vane pump is the correct choice as it plays a crucial role in providing hydraulic fluid for power steering systems. This pump is designed to create the necessary pressure in the hydraulic system, allowing the steering system to function smoothly and efficiently. When the driver turns the steering wheel, the rotary vane pump supplies the hydraulic fluid under pressure to the steering gear, assisting with steering effort and improving responsiveness.

While other components mentioned also play important roles in the power steering system, they do not provide the hydraulic fluid directly. The electric motor is typically used in electric power steering systems, while the hydraulic cylinder is a component that uses the hydraulic pressure generated but does not create it. The power steering fluid reservoir holds the hydraulic fluid but does not actively pump it into the system. Hence, the rotary vane pump stands out as the primary component responsible for generating hydraulic fluid pressure crucial for steering assistance.