18. Which of the following protocols is used to send an email message to the first server? a. POP3 b. IMAP4 c. SMTP d. FTP e. HTTP 19. Which DNS server offers the most current resolution to a DNS query? a. Root DNS Server c. Caching DNS Server e. Backup DNS Server b. Primary DNS Server d. TLD DNS Server 20. Jungle Travels Ltd. has established a consumer forum office in Minneapolis, which consists of five computers and a couple of printers and scanners, all of which are connected by a single hub. Which of the following network topologies would you have applied in such a scenario? a. Mesh b. Ring c. Star d. Bus c. Hybrid 21. A network consists of seven computers and a network printer, all connected directly to one switch. Which network topology does this network use? a. Client/Server c. Hub-and-spoke e. Bus b. Mesh d. Star 22. In the client-server model, what is the primary secure protocol used for communication between a browser and web server? a. HTTP b. HTTPS c. TLS d. 5SL e. SFTP 23. Which commonly used Network protocol uses the three-way handshake to establish a session between the two communicating hosts? a. UDP b. TCP c. IP d. ICMP e. Ping 24. Which of the following is a centralized directory database that contains user account information and security for the entire group of computers? a. Active Directory c. Workgroup e. MySQL b. Clients d. RAID 25. At which OSI layer does IP operate? a. Presentation b. Session C. Network d. Data Link e. Physical 26. Which OSI layer adds both a header and a trailer to the packet? a. Application b. Network c. Transport d. Data Link e. Physical 27. At what OSI layer does your browser's web page request begin its journey through the OSI layers? a. Application b. Session c. Network d. Data Link e. Physical 28. Which OSI layer adds both a header and a trailer to the data frame? a. Transport b. Data link c. Session d. Network e. Physical