Correct Response: B. The transport layer is responsible for data reliability and flow control. Depending on the requirements of the data transmission, the transport layer uses either the Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP) to encode the data for transport. The latter is used for VoIP because of its high speed and low latency. A is incorrect because the application layer consists of the higher-level applications that the host uses to interface with the transport layer. C is incorrect because the Internet layer is only responsible for routing data packets between hosts based on destination addresses. D is incorrect because the purpose of the data link layer is to control the flow of data across the physical network medium.
