a. Define the following terms in " in data communication [2marks each] i. Packet-switched networks ii. subnet mask iii. Routing Protocols iv. Intrusion Detection System (IDS) v. Demarcation Point b. Outline three advantages of dynamic routing protocols in WAN[6marks] c. Describe two common ways by which unauthorized users can gain access to a Wireless Local Area Network(WLAN) and how unauthorized access can be prevented. [4 marks]