Alice installed a new firewall that faces the Internet and protects her company's internal network. After she made that change, company users started complaining that they could not access websites or send or receive emails. What firewall issue is the most likely cause?

Firewalls are initially set with default ports and services disabled.

Her remote session to the firewall was hijacked.

She neglected to enable SOCKS.

When installing the firewall, she inadvertently took the mail and web servers offline.