The following statement about the functions of each layer of the OSI reference model is correct ______ . (Multiple choices)

The following statement about the functions of each layer of the OSI reference model is correct ______ . (Multiple choices)
A . The session layer is responsible for data format processing and data encryption.
B . The basic function of the transport layer is to establish and maintain virtual circuits, perform error checking and flow control.
C . The network layer determines the best route for transmitting packets. The key issue is to determine how the data packets are routed from the source to the destination.
D . The physical layer involves the original bit stream transmitted on the communication channel ( Channel ), which defines the mechanical, electrical functions, and regulations required to transmit data.
E . The application layer is responsible for providing network services for applications.

Answer: BCDE