This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Physiology
Carbon dioxide transpoed in blood mostly as 
Select and explain. 
A. Carnbon Hb, B. In combination with plasma proteins, C. Bicarbonate, D. Carbonic acid dissolved in plasma
C: Bicarbonate
Answer: C: Bicarbonate 
Explanation: Transpo of Carbon Dioxide in the Blood Carbon dioxide molecules are transpoed in the blood from body tissues to the lungs by one of three methods: dissolution directly into the blood, binding to hemoglobin, or carried as a bicarbonate ion. Several propeies of carbon dioxide in the blood affect its transpo Ref: guyton and hall textbook of medical physiology 12 edition page number:359,360,361