What accurately describes the flow control mechanism in an FC SAN?

A.
Both transmitting and receiving ports agree on the number of buffers available during port login

B.
Negotiation occurs between an E_Port and an F_Port, and between two N_Ports

C.
Credit value is incremented when a frame is transmitted and decremented upon receiving a response

D.
Receiver Ready (R_RDY) is sent from the receiving port if available credits reach zero

Explanation: