Which of the Following BEST Describes a firewall

Multiple Choice

Which of the following BEST describes a firewall?

A) A software and hardware system that prevents outsiders from accessing a company's internal 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 Web sites 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) An extranet site that gives customers access to different product lines