问题：

[单选]

The following was configured on a switch： 
Switch（config） # spanning-tree portfast bpdufilter default 
What is the effect of this configuration command？（）

A . If BPDUs are received by a port configured for PortFast， they are ignored and none are sent.
B . The command will enable BPDU filtering on all ports regardless of whether they are configured for BPDU filtering at the interface level.
C . If BPDUs are received by a port configured for Portfast， the port will transition to forwarding state.
D . If BPDUs are received by a port configured for PortFast， then PortFast is disabled and the BPDUs are processed normally.
E . None of the other alternatives apply.