What is the purpose of the cisco Vlan Trunking protocol?（）

A. to provide a mechanism to dynamically assign vlan membership to switch ports
B. to allow traffic to be carried from multiple vlans over a single link between switches
C. to allow native vlan information to be carried over a trunk link
D. to provide a mechanism to manually assign vlan membership to switch ports
E. to allow for managing the additions,deletions,and changes of vlans between switch