$5.$ Explain why collision is an issue in random access protocols? $6.$ What is the difference between unicast, multicast, and broadcast address? $7.$ What are some reasons that CSMA$/$CD cannot be used in a XF$02$ wireless LAN? $8.$ Assume that there are only two stations, A and B$,$ in a bus CSMA$/$CD network. The distance between the two stations is $2000$ m and the propagation speed is $2$x $10.$ m$/$s$.$ If the station A starts transmitting at time to: $($a$)$ Does the protocol allow station B to start transmitting at time t$.+8$ us$?$ if the answer is yes, what will happen? $($b$)$ Does the protocol allow station B to start transmitting at time ti $+11$ us$?$ if the answer is yes, what will happen? $9.$ How does the Ethernet address $1$A:$28$:$30$:$40$:$5$E:$6$F appear on the line in binary? I