Which of the following is a firewall rule that prevents internal users from accessing public FTP sites?
A. TCP ANY ANY ANY FTP Deny
B. TCP 192.168.42.0/24 ANY ANY 21 Deny
C. TCP 21 192.168.42.0/24 ANY ANY Deny
D. TCP ANY ANY 192.168.42.0/24 21 Deny
E. TCP FTP ANY ANY Deny
Answer: B