What is a CTA (Control Area)?

• A. Controlled airspace extending upwards from a specified limit above the earth
• B. Uncontrolled airspace at low altitude
• C. Airspace used only for military operations
• D. Airspace extending from ground to infinite

Answer: (A)

A Control Area is a defined block of airspace where ATC services are provided and where flights are subject to air traffic control clearances. It starts at a specified lower limit above the earth (not necessarily at the surface) and extends upward to a defined upper limit, forming a controlled region for en route traffic. This setup lets controllers manage separation for IFR and programmed VFR movements within that space.

That’s why the description of a controlled airspace extending upwards from a specified limit is the best fit. The other statements describe airspace that isn’t accurate for CTAs: it isn’t uncontrolled or limited only to military use, and it isn’t from ground to infinite.