CompTIA Network+ N10-006 Q405

A technician is installing a network firewall and would like to block all WAN to LAN traffic that is using ports other than the default ports for Internet and email connectivity. Which of the following rules should the technician verify FIRST?

A. All outbound traffic is blocked
B. All inbound traffic is blocked
C. A DMZ has been created
D. An implicit deny is enables

Correct Answer: D