a)  What does the "CD" mean in the CSMA/CD? How is it implemented in the Ethernet?  

b)  Consider an Ethernet hub with 8 ports and an Ethernet switch with 8 ports. In both cases (hub and switch), each port is rated at 100 Mbps. Assume that you use either the hub or the switch to create a small home network of 8 hosts. Which of the two networks (hub-based or switch-based) will be able to achieve a greater total network throughput (the total throughput is defined here as the sum of individual throughputs over all simultaneous communications between the hosts connected to the network)?  Why?  

c)  Name the protocol (i.e. give its well-known acronym and full name) responsible for finding the MAC address of a host from its IP address.