Which of the following would be considered a routing protocol？（）

单项选择题WhichofthefollowingnetworkservicesisresponsibleformappingnamestoIPaddresses？（）

A.DHCP
B.DNS
C.IMAP4
D.Telnet

单项选择题Whenoneconnectiontoahostfailsinafullmeshnetwork，whichofthefollowingistrue？（）

A.All hosts can communicate.
B.No hosts can communicate.
C.Half of the hosts will lose communication.
D.Only the two hosts between the failed connection will lose communication.