When conducting a penetration test, it is crucial to use all means to get all available information about the target network. One of the ways to do that is by sniffing the network. Which of the follow

Passive sniffing can identify operating systems, services, protocols, and devices by analyzing the headers and behavior of captured packets without sending any traffic.

Passive sniffing only observes and records packets as they traverse the network without sending any traffic of its own. Modifying captured packets and replaying them onto the network is an active technique - it requires injecting new or altered frames - which by definition cannot be accomplished through passive monitoring alone.

Capturing unencrypted credentials (such as those sent over Telnet or HTTP) is a classic passive sniffing capability that requires no active packet injection.

Capturing traffic for later offline analysis is the fundamental purpose of passive sniffing and is entirely achievable without active network interaction.