<span>A large organization minimum at-least 2 DNS servers are needed. DNS servers are each internet domain in need. and Multiple server farms distribute the DNS Server. One of the DNS Server is must in separate location. install DNS server on all domain controller. DNS server on every domain controller is must.</span>
Joseph Henry in about 1835. He is American and he made something called a relay.
Update and measure those are the only understand answers
B. Internet Telephony would be my best guess. I'm not that good with computers. Hope this Helps :-)
My opinion is the answers A and D. I would choose A if you can only choose one, though.