What are the benefits of high-altitude training for athletes concerning BPG concentration and oxygen release adaptation?

• A. High-altitude training increases BPG concentration, enhancing oxygen release upon return to sea level.
• B. High-altitude training has no effect on BPG concentration or oxygen release.
• C. High-altitude training stabilizes BPG concentration, maintaining constant oxygen release.
• D. High-altitude training decreases BPG concentration, reducing oxygen release upon return to sea level.

Answer: (A)