Comprehensive and Detailed in Depth Explanation:

A Demilitarized Zone (DMZ) is a standard network security construct used to enhance the protection of an organization’s internal network. Per NIST SP 800-171 and CMMC Level 2 guidelines (e.g., SC.L2-3.13.6), a DMZ logically separates public-facing services, such as web servers, from the internal network containing sensitive data like CUI. This logical isolation is achieved through firewalls, access control lists (ACLs), or routing configurations, not physical separation, reducing the risk of external threats penetrating the internal network.

Option A (physical isolation) misrepresents the DMZ’s logical nature. Option B (physical security) pertains to facility controls, not network architecture. Option C (unrestricted access) contradicts the DMZ’s purpose of controlled access. Option D correctly identifies the DMZ’s role in logical isolation, making it the correct answer.

Reference Extract:

NIST SP 800-171, 3.13.6:“Deny network communications traffic by default and allow by exception… achieved through logical segmentation like a DMZ.”

CMMC AG Level 2, SC.L2-3.13.6:“A DMZ isolates public-facing services from internal networks logically.”Resources:https://csrc.nist.gov/pubs/sp/800/171/a/final ;https://dodcio.defense.gov/Portals/0/Documents/CMMC/AG_Level2_MasterV2.0_FINAL_202112016_508.pdf