Which AAC category covers speeds from 91 to less than 121 knots?

The correct answer focuses on understanding the classification of aircraft speed categories as outlined by the FAA in the context of air traffic control and airport operations. AAC Category B specifically encompasses aircraft that have a stall speed of 91 knots or more but less than 121 knots. This categorization is crucial for airport operations, particularly in determining appropriate separation minimums for air traffic, handling approach and departure procedures, and ensuring safety during ground operations.

Each AAC category aligns with certain speed ranges to assist in managing the flow of air traffic and define the operational requirements for different types of aircraft. This categorization is essential for air traffic controllers and airport managers to ensure safe and efficient operations in various phases of flight. Understanding these categories improves situational awareness and contributes to overall safety in the aviation environment.

In contrast, the other categories cover different speed ranges, hence they would not apply to the specified range of 91 to less than 121 knots.