How does an increase in BPG concentration at high altitudes affect hemoglobin's oxygen release and binding curve?

• A. It has no effect on the binding curve or oxygen release.
• B. It shifts the binding curve to the left, reducing oxygen release.
• C. It shifts the binding curve to the right, enhancing oxygen release.
• D. It shifts the binding curve to the right, reducing oxygen release.

Answer: (C)