Which of the following is not one of the five OE domains?

• A. Maritime
• B. Land
• C. Urban
• D. Cyberspace

Answer: (C)

The concept being tested is recognizing the official operating environment domains. The five OE domains are land, maritime, air, cyberspace, and space. Urban describes a specific setting or terrain within those domains—cities and built-up areas—but it is not listed as a separate domain on its own. Operations in urban areas occur within the broader domains (often land, and potentially intersecting cyberspace or space aspects), but “urban” by itself isn’t categorized as one of the five domains. That’s why the option describing an urban environment isn’t a domain, making it the correct choice.