What is the transition of states when PortFast is configured?

A. Forwarding, listening, learning, blocking
B. Listening, forwarding, learning, blocking
C. Listening, learning, forwarding, blocking
D. Blocking, listening, learning, forwarding

A. PortFast mode allows an interface to bypass the blocking state and begin forwarding immediately. It then listens and learns of BPDUs on the interface and can make a decision to continue to forward frames or enter into a blocking state.