When configuring private VLANs, which configuration task must you do first?

A.
Configure the private VLAN port parameters.

B.
Configure and map the secondary VLAN to the primary VLAN.

C.
Disable IGMP snooping.

D.
Set the VTP mode to transparent.

Explanation:
When you configure private VLANs, the switch must be in VTP transparent mode. Because VTP
does not support private VLANs, you must manually configure private VLANs on all switches in the
Layer 2 network. If you do not configure the primary and secondary VLAN association in some
switches in the network, the Layer 2 databases in these switches are not merged. This can result
in unnecessary flooding of private-VLAN traffic on those switches.
Reference:
http://www.cisco.com/en/US/docs/switches/lan/catalyst3750/software/release/12.2_25_see/config
uration/guide/swpvlan.html