Which of the following BEST describes an extranet?

A. a software and hardware system that prevents outsiders from accessing a company's network
B. a tool that searches Web pages containing the user's search terms and then displays pages that match
C. a private network of internal websites and other sources of information available to a company's employees
D. an Internet connection allowing outsiders limited access to a firm's internal information system
E. a delivery system linked to production schedules