Which security control examines a data packet traversing a network and compares it to a...

A firewall is the network security control specifically designed to inspect data packets as they traverse a network boundary and evaluate each packet against a configured set of filtering rules, based on criteria such as source and destination IP address, port number, protocol, or, in more advanced stateful and next-generation firewalls, application-layer content and connection state, ultimately permitting or blocking the packet according to those rules. This packet-inspection-and-rule-matching function is the defining, textbook characteristic of a firewall, directly matching the description given in the question. A VPN (A) establishes an encrypted tunnel between two endpoints to protect data confidentiality and integrity as it traverses an untrusted network, such as the public internet; while it secures traffic in transit, it does not itself perform rule-based packet filtering and inspection the way a firewall does. Zoning (B) is a storage-area-network security mechanism that restricts which host bus adapters (HBAs) can communicate with which storage ports within a Fibre Channel fabric, operating at the SAN fabric level rather than inspecting general network packets against filtering rules. LUN masking (C) is a storage-level access control that restricts which hosts are permitted to see and access specific logical unit numbers (LUNs) on a storage array, again a storage access control rather than a network packet-filtering mechanism. Firewall is correct.

Reference topic: Securing the Data Protection Environment - Firewalls and Network Packet Filtering.