8. Since IP is a best-effort' protocol, how do we know that a packet will be delivered to its destination host? TU A. We make sure that we use the appropriate M B. Internet links and routers are very reliable these days. C. We use a more complex protocol such as TCP D. Routing tables are continuously updated, so there is always a pat E. Higher-layer protocols will always detect a lost packet and resend it. 9. This question relates to Classless Inter-Domain Routing (CIDR). Which of the following statements is/are true? X. It is a flexible scheme for managing host IDs. Y. It reduces the chance of an Ethernet link getting congested. Z. CIDR was introduced as part of the OSI model as a way of increasing flexibility between layers. A. X only B. Y only C. Z only D. None of X, Y, and Z E. All, or two of X, Y, and Z