About the RJ31X jack, which statement is true?

• A. It provides line seizure but does not prioritize alarm signals
• B. It prevents any dial-out during an alarm
• C. It allows the alarm system to retrieve a dial tone even if the telephone is in use or off-hook
• D. It disables the telephone line for the duration of the alarm

Answer: (C)

The key idea is that an RJ31X jack acts to seize the telephone line so the alarm controller can dial out when an alarm occurs. When the panel triggers, the RJ31X takes control of the line from any current use and provides the dial tone to the alarm system, even if someone is on the phone or the line is off-hook. This ensures the alarm can communicate with the monitoring station without being blocked by a busy line.

That’s why the statement about retrieving a dial tone despite the telephone being in use best captures its function. It’s not about preventing dial-out or permanently disabling the line; it’s about guaranteeing the alarm can access the line and complete its outbound call during an alarm.