Which statement is TRUE regarding network firewalls preventing Web Application attacks?

Which statement is TRUE regarding network firewalls preventing Web Application attacks?

A.
Network firewalls can prevent attacks because they can detect malicious HTTP traffic.

B.
Network firewalls cannot prevent attacks because ports 80 and 443 must be opened.

C.
Network firewalls can prevent attacks if they are properly configured.

D.
Network firewalls cannot prevent attacks because they are too complex to configure.