The correct answer is C) stop-check/stop valves. The valves at point "A" in the system illustrated in SG-0005 are stop-check/stop valves. These types of valves are commonly used in marine applications to control the flow of fluids and provide a means of isolating equipment for maintenance or emergency purposes. Stop-check/stop valves combine the functions of a stop valve (which can be opened and closed to control flow) and a check valve (which allows flow in only one direction), making them a versatile choice for many marine systems. The other answer choices are incorrect because they do not accurately describe the type of valves depicted in the illustration. Swing check/stop valves, globe valves/gate valves, and gauge valves/drain valves have different functionalities and are not the specific type of valves used at point "A" in the SG-0005 system.