An internet is a combination of networks connected by（71) .When a datagram goes from a sou

An internet is a combination of networks connected by (71) .When a datagram goes from a source to a (72) ，it will probably pass many (73) until it reaches the router attached to the destination network．A router receives a (74) from a network and passes it to another network．A router is usually attached to several networks．When it receives a packet，to which network should it pass the packet？ The decision is based on optimization： Which of the available (75) is the optimum pathway？

A．modems

B．routers

C．switches

D．computers