Which three elements must be used when you configure a router interface for VLAN
trunking? (Choose three.)

A.
one physical interface for each subinterface

B.
one IP network or subnetwork for each subinterface

C.
a management domain for each subinterface

D.
subinterface encapsulation identifiers that match VLAN tags

E.
one subinterface per VLAN

F.
subinterface numbering that matches VLAN tags

Explanation:
This scenario is commonly called a router on a stick. A short, well written article on this
operation can be found here:
http://www.thebryantadvantage.com/RouterOnAStickCCNACertificationExamTutorial.htm