Explanation/Reference:
An intranet is a computer network that uses Internet Protocol technology to share information, operational systems, or computing services within an organization. This term is used in contrast to extranet, a network between organizations, and instead refers to a network within an organization.

Tunneling enables the encapsulation of a packet from one type of protocol within the datagram of a different protocol. For example, VPN uses PPTP to encapsulate IP packets over a public network, such as the Internet.

Explanation/Reference:
VLANs provide the following advantages:
* (E) VLANs enable logical grouping of end-stations that are physically dispersed on a network. ...
* VLANs reduce the need to have routers deployed on a network to contain broadcast traffic. ...
* (C) Confinement of broadcast domains on a network significantly reduces traffic.
By confining the broadcast domains, end-stations on a VLAN are prevented from listening to or receiving broadcasts not intended for them.
* (B) If a router is not connected between the VLANs, the end-stations of a VLAN cannot communicate with the end-stations of the other VLANs.