What will the command of spanning-tree portfast default entered in global configuration mode do?

A. Turn on PortFast mode for all ports.
B. Turn on PortFast mode for all access ports only.
C. Turn off spanning tree on all ports.
D. Turn off spanning tree on all access ports only.

B. This command turns on PortFast globally for only access ports on the switch. This command should be used on access switches because end devices are connected at this level in the hierarchy.