What is a plumbing device that controls the flow of water for toilets and urinals known as?

The correct answer is the flushometer valve. This device is specifically designed to control the flow of water to toilets and urinals, enabling them to flush effectively without the need for a tank. Flushometer valves work by using water pressure to force a predetermined amount of water into the bowl when activated, ensuring efficient and effective flushing.

In contrast to other options, the toilet tank is a storage component that holds water until it is needed for flushing, rather than controlling the flow directly. A shutoff valve is used to stop the flow of water to a fixture or area, providing control but not specifically designed for flushing purposes. The pressure regulator helps maintain water pressure within specified limits and is not a device used primarily for controlling how water is delivered to toilets or urinals. Thus, the flushometer valve accurately reflects the plumbing device that serves the intended function in restroom operations.