A _____ is designed to operate in the _____.

• A. Core router, Internet backbone
• B. Switch, Local area network
• C. Modem, public network
• D. Firewall, DMZ

Answer: (A)

This item tests where network devices operate. A core router is designed to move large amounts of traffic between major networks, forming the Internet backbone. It handles high-capacity routing and interconnects different ISPs and data centers, which is why it belongs in the Internet backbone. In contrast, a switch stays inside a local area network to forward frames between local devices; a modem connects a user to a public network for Internet access; a firewall placed in a DMZ serves as a security boundary rather than part of the backbone. So, the pairing of core router with Internet backbone best fits how these components are used in real networks.