How does cellular respiration in tissues contribute to hemoglobin's oxygen release?

Cellular respiration decreases CO2 levels, increasing hemoglobin's oxygen affinity.

Cellular respiration has no effect on hemoglobin's oxygen release.

Cellular respiration increases oxygen concentration, enhancing hemoglobin's oxygen binding.

Cellular respiration produces CO2, which diffuses into the bloodstream and decreases hemoglobin's oxygen affinity.