What are the switch and bridge port characteristics of a layer two spanning-tree network that is fully converged?（）

A、All switch and bridge ports are in the forwarding state.

B、All switch and bridge ports are in the stand-by state.

C、All switch and bridge ports are assigned as either root or designated ports.

D、All switch and bridge ports are in either the forwarding or blocking state.

E、All switch and bridge are either blocking or looping.