Which of the following is NOT a VLAN Trunking Protocol (VTP) mode of operation?

A.
client

B.
server

C.
virtual

D.
transparent

Explanation:
Virtual is not a valid VTP mode of operation. There are three different VTP modes of operation: client, server,
and transparent.
In client mode, a switch can synchronize VLAN information with the domain and forward advertisements.
However, VLANs cannot be created, deleted, or modified from a switch in client mode. Also, a client mode
switch does not save VLAN information in non-volatile Random Access Memory (NVRAM). It is stored in Flash
in a file called vlan.dat.
In server mode, a switch synchronizes the VLAN information with the domain, sends and forwards
advertisements, and can create, delete, or modify VLANs. In server mode, VLAN information is stored in Flash
in a file called vlan.dat.
In transparent mode, a switch does not synchronize its VLAN configuration with the domain, but it forwards
advertisements. VLANs can be created, deleted, or modified locally and VLAN configuration is saved in both
the running-config file in RAM and in flash in a file called vlan.dat.
Objective:
LAN Switching Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot VLANs (normal/extended range) spanning multiple switches

Cisco > Catalyst 4500 Series Switch Cisco IOS Software Configuration Guide, 12.2(25) > Understanding and
Configuring VLANs, VTP, and VMPS