What is the NIDS primary function in the SAFE SMR midsize network design corporate Internet module?

A.
Provide connectivity to the campus module.

B.
Provide connectivity to the WAN module.

C.
Provide connectivity to the LAN module.

D.
Provides detection of attacks on ports that the firewall is configured to permit.

E.
Provide the demarcation point between the ISP and the medium network.

F.
Provide connection state enforcement and detailed filtering for session initiated through the firewall.

Explanation:

The public services segment includes a NIDS appliance. Its primary function is to detect attacks on ports that the firewall is configured to permit. These most often are application layer attacks against specific services.
Reference: SAFE: Extending the Security Blueprint to Small, Midsize, and Remote-User Networks Page 19