The correct option is C Assertion is correct but Reason is incorrect
When dissolved in water, carbon dioxide forms carbonic acid, H2CO3. Carbonic acid can lose protons. The loss of protons in a solution is what makes that solution acidic. The carbonate buffer system controls the pH levels in blood. PH is a measurement of acidity. The lower the pH, the more acidic a solution is. Carbon dioxide is an essential part of the carbonate buffer system. When carbon dioxide is dissolved in the blood, it creates a buffer composed of bicarbonate ions, HCO3− , carbonic acid, H2CO3, and carbon dioxide, CO2. All three exist in equilibrium with each other. The carbonic acid part of the buffer can neutralize hydroxide ions, which increases the pH of the blood, while the bicarbonate part of the system can neutralize hydrogen ions, which decreases the pH of the blood. CO2 is the waste product of cells that must be removed from the body so we can take in oxygen.