Which description of a passive interface on a Cisco Firepower NGFW is true?

A passive interface on a Cisco Firepower NGFW is configured for out-of-band monitoring to receive copies of network traffic, typically from a SPAN port, for analysis. This traffic is then processed by the NGIPS engine to detect intrusion events and other threats based on defined policies without impacting the traffic flow.

An interface that is disabled would be inaccessible regardless of its mode, and this is not a unique characteristic or primary function of a passive interface.

Passive mode is itself an interface configuration mode; it is not 'effected by' other firewall modes like routed or transparent, but rather defines its own operational behavior for monitoring.

Passive interfaces are strictly for monitoring (listening to) traffic; they do not retransmit received traffic back into the network.