Which three of these statements regarding 802.1Q trunking are correct? (Choose three.)

A.
802.1Q native VLAN frames are untagged by default.

B.
802.1Q trunking ports can also be secure ports.

C.
802.1Q trunks can use 10 Mb/s Ethernet interfaces.

D.
802.1Q trunks require full-duplex, point-to-point connectivity.

E.
802.1Q trunks should have native VLANs that are the same at both ends.

Explanation:
Native VLAN frames are carried over the trunk link untagged
802.1Q trunking ports carry all the traffic of all VLANs so it cannot be the secure ports. A secure
port should be only configured to connect with terminal devices (hosts, printers, servers…)
The Inter-Switch Link (ISL) encapsulation requires FastEthernet or greater to operate but 802.1q
supports 10Mb/s Ethernet interfaces. –
802.1Q supports point-to-multipoint connectivity. Although in Cisco implementation, a “trunk” is
considered a point-to-point link but 802.1q encapsulation can be used on an Ethernet segment
shared by more than two devices. Such a configuration is seldom needed but is still possible with
the disablement of DTP negotiation. -> (Reference:
http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a008012ecf3.
shtml)
The native VLAN that is configured on each end of an 802.1Q trunk must be the same. This is
because when a switch receives an untagged frame, it will assign that frame to the native VLAN. If
one end is configured VLAN1 as the native VLAN while the other end is configured VLAN2 as the
native VLAN, a frame sent in VLAN1 on one side will be received on VLAN2 on the other side ->