What component might be installed to detect attempts to cut a phone line?

The line security monitor is specifically designed to detect disruptions or tampering with phone lines used for alarm communication. This component continuously monitors the integrity of the phone line and can trigger an alert if the line is cut or otherwise compromised. This is critical for alarm systems that rely on phone lines for signaling to a central monitoring station or for communicating during an emergency.

In contrast, a motion sensor is utilized to detect movement within a specified area and does not have the capability to monitor phone lines. A video camera serves the purpose of visual surveillance but is not designed to assess the functionality of communication lines. A smoke detector is focused on identifying smoke or fire, which also does not relate to the monitoring of phone line integrity. Thus, the line security monitor is the essential component for ensuring that any cuts or attempts to disable phone line communication are promptly detected.