What does a rightward shift in the oxygen binding curve indicate about hemoglobin's oxygen affinity in tissues?

• A. A rightward shift indicates hemoglobin's preference for CO2 binding.
• B. A rightward shift indicates increased oxygen affinity, promoting oxygen binding.
• C. A rightward shift indicates decreased oxygen affinity, promoting oxygen release.
• D. A rightward shift indicates no change in oxygen affinity.

Answer: (C)