The correct answer is C) swing check valve. A swing check valve is a type of check valve that uses a hinged flap to allow flow in one direction but prevent backflow. The flap is connected to a hinge that allows it to swing open when flow is in the desired direction, but swing shut to block reverse flow. This is the type of valve depicted in the illustration GS-0056. The other answer choices are incorrect because they do not accurately describe the type of valve shown. A lift gate valve, butterfly lift valve, and swing globe valve have different internal mechanisms and operating principles that do not match the illustration.