The protocol used for interdomain routing is:() A. BGP B. TCP C.IP D. RIP

The correct answer is A. BGP.

BGP, or the Border Gateway Protocol, is the protocol used for interdomain routing. It is an important exterior gateway protocol that allows different autonomous systems (AS) to communicate with each other over the Internet. BGP is responsible for exchanging routing and reachability information among these autonomous systems, enabling the Internet to function as a global network of networks.

The other options:

• TCP (Transmission Control Protocol) is a transport layer protocol that manages communication between nodes on a network.
• IP (Internet Protocol) is a network layer protocol that provides the addressing and routing mechanisms that allow data to be sent between computers on a network.
• RIP (Routing Information Protocol) is an internal gateway protocol used for routing within a single autonomous system.