Which of the following is a process of monitoring data packets that travel across a network?

SCP (Secure Copy Protocol) is a file transfer protocol that securely copies files between hosts over SSH and is not used to monitor network traffic.

Packet sniffing works by placing a network interface into promiscuous mode, allowing it to capture all packets passing through the network segment regardless of destination. Tools such as Wireshark and tcpdump implement this technique to monitor traffic content, detect anomalies, and diagnose network issues. This directly matches the definition of monitoring data packets traveling across a network.

A rootkit is a category of malicious software designed to gain persistent privileged access to a system while hiding its presence, unrelated to network packet monitoring.

ICMP (Internet Control Message Protocol) is a network-layer protocol used for sending error messages and operational information such as ping diagnostics, not for monitoring data packets.