Explanation: NetFlow is a network protocol developed by Cisco for the collection and monitoring of network traffic flow data generated by NetFlow-enabled routers and switches. The flows do not contain actual packet data, but rather the metadata for communications. It is a standard form of session data that details who, what, when, and where of network traffic -> Answer A is not correct. Reference: https://www.cisco.com/c/en/us/solutions/collateral/enterprise-networks/enterprise-network-security /white-paper-c11-736595.html