An intrusion system should NEVER have hardware options that include _____.

An intrusion system should never have hardware options that include normally open unsupervised detectors because these types of detectors can be highly vulnerable to tampering and faults. Normally open unsupervised detectors operate in a way that they are unmonitored and rely on changes in the environment or the status of the monitored object to trigger an alarm. If a security breach occurs, these detectors may fail to detect the intrusion because they do not provide a feedback mechanism or a way to confirm their operational status.

In contrast, options such as digitally monitored sensors, wireless communication devices, and dual technology detectors enhance the reliability and effectiveness of an intrusion detection system. Digitally monitored sensors provide real-time feedback and can alert the system to potential issues, while dual technology detectors combine different sensing methods to reduce false alarms, and wireless communication devices offer flexible installation and networking capabilities. Therefore, having normally open unsupervised detectors in an intrusion system can create significant security risks, making them an undesirable choice.