Explore the World of Firearms: Pump Action

Explanation:

In the context of firearms, pump action refers to a manual cycling of the weapon's action to eject a spent cartridge and load a new one, typically by sliding a forend or handle backwards and forwards. This is distinct from other firing mechanisms such as Brake Action, which usually involves breaking open the barrel to load shells, Bolt Action, where a handle is manually operated to chamber rounds, and Semi-Automatic, where the cycling of a new round into the chamber is automatically done after each shot without manually manipulating the weapon.

Thus, the correct option is A.