The casing of a pump encloses the pump along with which additional component?

The correct choice highlights that the casing of a pump indeed encloses not only the impeller — the key component responsible for moving fluid — but also the stuffing box, which is crucial for preventing leaks along the shaft that connects the impeller to the motor.

The impeller is the rotating part that creates the flow of fluid, and its shape and design are essential for the pump's efficiency in transferring energy to the liquid. The stuffing box facilitates a seal around the shaft to minimize leakage while allowing the shaft to rotate freely. This combination within the casing is fundamental to the pump's operation, ensuring that the flow generated by the impeller remains contained and effective, while managing any potential leaks that could disrupt the system.

The other components listed, while related to the operation of a pump, do not form part of the casing itself. The inlet screen is generally located at the intake of the pump to filter out large particles before the fluid enters; the discharge manifold is part of the piping system that directs fluid out of the pump; and while the pump motor is a critical component that powers the impeller, it is not enclosed within the pump casing itself. Thus, the casing primarily includes the impeller and stuffing box, making this the most accurate answer.