A routing table is used by a router to

• A. Store user credentials
• B. Determine the most efficient path to reach a destination
• C. Encrypt data
• D. Filter traffic by policy

Answer: (B)

The main idea is how a router uses a routing table to forward packets toward their destination by choosing the best next hop. A routing table lists destination networks, the next hop or exit interface to reach them, and metrics that help compare paths. When a packet arrives, the router searches the table for the best match for the destination IP and forwards the packet along the path with the most favorable metric, effectively selecting the most efficient route to reach the destination.

Storing user credentials, encrypting data, and filtering traffic by policy are handled by other mechanisms. Credentials are managed by authentication systems, encryption is applied by encryption protocols or VPNs, and traffic filtering is done with access control lists or firewall rules rather than by the routing table.