Which of the following is necessary for each of the firewalls to allow private IP addresses to be passed on to the Internet?

Consider the following diagram involving two firewall-protected networks:

Which of the following is necessary for each of the firewalls to allow private IP addresses to be
passed on to the Internet?

A.
Chargeback

B.
Stateful multi-layer inspection

C.
Masquerading

D.
DMZ creation