Which statement correctly describes enabling BPDU guard on an access port that is also enabled
for PortFast?

A.
Upon startup, the port transmits 10 BPDUs. If the port receives a BPDU, PortFast and BPDU
guard are disabled on that port and it assumes normal STP operation.

B.
The access port ignores any received BPDU.

C.
If the port receives a BPDU, it is placed into the error-disable state.

D.
BPDU guard is configured only globally and the BPDU filter is required for port-level
configuration.

Explanation:
When enabled on a port, BPDU Guard shuts down a port that receives a BPDU. When configured
globally, BPDU Guard is only effective on ports in the operational PortFast state. In a valid
configuration, PortFast Layer 2 LAN interfaces do not receive BPDUs. Reception of a BPDU by a
PortFast Layer 2 LAN interface signals an invalid configuration, such as connection of an
unauthorized device. BPDU Guard provides a secure response to invalid configurations, because
the administrator must manually put the Layer 2 LAN interface back in service. With release
12.1(11b)E, BPDU Guard can also be configured at the interface level. When configured at the
interface level, BPDU Guard shuts the port down as soon as the port receives a BPDU, regardless
of the PortFast configuration.
Reference:
http://www.cisco.com/en/US/docs/routers/7600/ios/12.1E/configuration/guide/stp_enha.html#wp1020395