Concept:An intranet is a private internal network, while an extranet extends access to selected outside users.
Explanation:An intranet is built using internet technologies but is restricted to members of one organization.
It is used only by employees and staff for internal communication and collaboration.
An extranet, however, allows approved external parties such as clients, vendors, or partners to access some parts of the intranet.
Therefore, the main distinguishing feature of an intranet is that access is limited to employees of the organization.
It is not open to the general public, and it does not differ from an extranet by requiring a modem or internet protocols.
Answer:C. is restricted to employees of an organization.