16. Which of the following are TCP/IP protocols used at the Application layer of the OSI model?

1. IP
2. TCP
3. Telnet
4. FTP
5. TFTP

A. 1 and 3
B. 1, 3 and 5
C. 3, 4 and 5
D. All of the above

17. What protocol is used to find the hardware address of a local device?

A. RARP
B. ARP
C. IP
D. ICMP

18. Which of the following protocols uses both TCP and UDP?

A. FTP
B. SMTP
C. Telnet
D. DNS

19. What is the address range of a Class B network address in binary?

A. 01xxxxxx
B. 0xxxxxxx
C. 10xxxxxx
D. 110xxxx