RSTP has made many improvements to STP. Which of the following is not an improvement of RSTP to STP?

Although the STP protocol can solve the loop problem, the slow convergence of the network topology affects the user communication quality.

RSTP has made many improvements to STP. Which of the following is not an improvement of RSTP to STP?
A . RSTP has deleted 3 kinds of port states and added 2 kinds of port roles.
B . The RSTP port state specification is based on whether the port forwards user traffic and learns the MAC address, reducing the original five port states to three.
C . The non-root switch running RSTP sends configuration BPDUs at the interval specified by the Hello Timer. This behavior is completely performed by each device.
D . If a port does not receive configuration BPDUs from the upstream device within 4 consecutive Hello Time durations, the device considers that negotiation with this neighbor fails.

Answer: D