单项选择题

For each blank, choose the best answer from the four choices and write down on the answer’sheet.
() is a protocol that a host uses to inform a router when it joins or leaves an Internet multicast group.
() is an error detection code that most data communication networks use.
() is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.
() is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non-periodic basis over a range of media.
() is an identifier of a web page.

() is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.

A.OSPF
B.RIP
C.RARP
D.BGP