Which description correctly characterizes the Beep (multistage shuttle) test, including a common limitation?

• A. A laboratory treadmill test that measures maximal oxygen consumption directly.
• B. A test assessing vertical jump power.
• C. A 5 km run to assess endurance.
• D. A field test where participants run 20 m shuttles at increasing speeds; limitations include motivation, pacing, familiarity, and environmental factors.

Answer: (D)