4. Figure 1 shows a network topology on how computers can communicate across LAN and WAN via different types of physical media and Layer 2 protocols. The following questions are based on the figure below. 0000 PPP HDLC Frame Relay B Figure 1 Page 2 of 8 a) The label "A" and "B" on Figure 1 are two different popular network connections for LAN. Identify the type of connecting media and the IEEE Networking Standard of LAN "A" and "B" respectively. (4 marks) b) There are two types of access method in LAN topology. State the access method used for both "A" and "B". c) Explain the type of access method mentioned in question 4(b). (2 marks) (4 marks) (CLO2:PLO2:C2) Question 6 (7 points): The purpose of the physical layer is to transport a raw bit stream from one machine to another. a) (2 points) List two types of physical media that can be used for actual transmission in Local Area Networks (LANS). b) (4 points) Compare the types you listed considering: bandwidth, noise immunity, cost, and typical distances used for the media types. c) (1 point) To connect your computer to an Ethernet LAN you need a network interface card (NIC) or network adapter. Which OSI layers represent the functions of a NIC?