Which code represents the Switch repeater relay?

• A. Vb
• B. Wz
• C. Wp
• D. Wpbx

Answer: (C)

In signaling code nomenclature, each device gets a concise code that shows its type and function. The first letter often signals the broad device family, and the second letter pinpoints the specific role within that family. For switch-related devices, the base is W, and the second letter indicates what the device does. The letter p stands for a repeater function, so Wp is the code used for the switch repeater relay. That’s why this option best matches the switch repeater relay.

The other options don’t fit because they would refer to different device types or functions within the signaling system (for example, a different first-letter family or a different second-letter meaning). A longer, multi-letter form isn’t the standard two-letter code used for identifying the switch repeater relay.