Carbon Dioxide (CO2) Is Readily Soluble in Water, According to the Equation

Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2 into the bloodstream. What will be the effect on the pH of blood as that blood first comes in contact with respiring cells?

A) Blood pH will decrease slightly.
B) Blood pH will increase slightly.
C) Blood pH will remain unchanged.
D) Blood pH will first increase, then decrease as CO2 combines with hemoglobin.
E) Blood pH will first decrease, then increase sharply as CO2 combines with hemoglobin.