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 is present maximally in 
Select and explain. 
A. Dissolved form, B. HCO3 form, C. RBC's, D. Plasma
B: HCO3 form
Answer: B: HCO3 form 
Explanation: Bicarbonate (HCO3-) is an anion of carbonic acid in which only one of the hydrogen atoms have been removed, as in sodium bicarbonate (NaHCO3). Also called hydrogen carbonate.Ref: Ganong&;s review of medical physiology; 23ed edition, page no: 612