Which option BEST represents a fail-closed scenario in a network security context?
A network monitoring system alerts administrators when a failure in the intrusion detection system is detected.
When a firewall encounters a failure, it ceases to pass any traffic, effectively isolating the internal network.
A critical server automatically reboots itself in response to an application crash to maintain service availability.
A malfunctioning firewall defaults to allowing all inbound and outbound traffic without restriction.