4. a. For the following question: Give THREE general examples of Application-layer Applications. b. State a NAME/BRAND of an ACTAUAL application that is representative of the application in part (a). State the Application-layer protocol for each of the three examples. d. State the underlying TRANSPORT protocol upon which the application-layer protocol is built. c. For this problem, organize your answers into a table (for example [totally fake]): General Application Actual Product Application-layer Underlying Protocol Transport Protocol Monkey Mozilla MokeyApp MAP UDP (by ThunderApp) Obviously, your table should have three rows for each example, excluding the 'header row ?. 5. Why isn't the SMTP protocol used to fetch email from a mail server? What protocols are used instead for this purpose? 6. State the two ways in which all hosts are identified on the Internet