Which of the following is NOT a type of pump?

C is not a type of pump because it refers to a type of separation device used in various industrial processes, such as air classification and material handling, rather than a device specifically designed for moving fluids. This device uses centrifugal forces to separate materials, but it doesn't function to pump liquids, which is the primary purpose of the other options listed.

In contrast, submersible pumps are designed to operate while submerged, pushing fluids to the surface. Centrifugal pumps utilize a rotating impeller to move fluid, relying on the principle of centrifugal force. Reciprocating pumps operate on a mechanism that uses a piston to move fluids through a cylinder. Each of these options represents a specific type of pump that moves liquids in various applications.