(a) Name three non-proprietary Internet applications and the application layer protocols that they use. [3 marks] (b) Compare the connectivity mechanism in persistent Hypertext Transfer Protocol (HTTP) and non-persistent HTTP. List three referenced objects that could be contained within a webpage. [9 marks] (c) Does Webmail use POP3, IMAP, or neither? If one of these, why was that one chosen? If neither, which one is it closer to in spirit? [4 marks] (d) Describe the advantages of file distribution using Peer-to-Peer architecture compared to Client-Server model. [4 marks]