It is recommended in the passage as a security measure that people should ______.

A．New vulnerabilities will be introduced into your environment every day.
B．The manager educates employees about properly configuring firewalls and intrusion detection systems for their PCs.
C．Managers have more responsibility than ever.
D．Security managers are asked to support increasing degrees of network availability and access.

A．highly recognizable names behind many of the computer technologies used today
B．the negative connotation of those computer users
C．a game, employing the tools that are readily available via the Internet
D．people who break into computer systems