1. C. Explanation: Differentiating and prioritizing types of traffic is an example of QoS.
2. Scalability, security, data integrity, and fault tolerance. Explanation: In order, the best terms are scalability, security, data integrity, and fault tolerance.
3. D. Explanation: Packet switching allows for messages to be sent along multiple paths. Circuit switching and leased lines use dedicated paths.
4. C. Explanation: Intranets connect LANs and WANs that should only be accessible by internal employees, whereas an extranet allows an organization to do business directly with other, external organizations by allowing them access to part of the internal network.
5. B. Explanation: ...