The correct answer is sFlow. It is used for traffic monitoring and is designed to be scalable and efficient, enabling IT professionals to analyze sampled network traffic in high-speed networks. sFlow allows for continuous monitoring, which is essential for identifying and reacting to incidents swiftly, especially in a case where unusual traffic needs to be analyzed. The incorrect answers, SNMP and RMON, might seem plausible because they are also used in network monitoring; however, SNMP is generally used for managing network devices, not for traffic analysis, and RMON is an older standard for remote network monitoring that doesn't have the same scalability for high-speed network traffic analysis as sFlow. Tcpdump is a tool for capturing packets but it does not provide the scalability and sampling features that are inherent to sFlow.