The code NDU corresponds to which name?

• A. Horizon
• B. Sioux
• C. Quantas
• D. National Cargo

Answer: (B)

In aviation identification, U.S. aircraft registrations start with the letter N, and the characters that follow serve as the unique tail number used as the flight’s radio identification in many training contexts. In practice tests, a three-letter block like NDU is often tied to a specific operator name within the provided dataset to help you memorize or recognize who the aircraft represents. Here, the dataset maps NDU to Sioux, so hearing or seeing NDU aligns with the Sioux operator. The other names aren’t linked to this particular registration block in the material, so they don’t fit as the corresponding operator for NDU. In real life, you’d verify the exact owner in the FAA registry, but for this test the intended association is Sioux.