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
Physiological response to smoking, are all, except 
Select and explain. 
A. Decreased HDL, B. Increased hematocrit, C. Increased hea rate and increased catecholamine release, D. Decreased carboxyhemoglobin
D: Decreased carboxyhemoglobin
Answer: D: Decreased carboxyhemoglobin 
Explanation: Carboxyhemoglobin increases in smokers Ref: guyton and hall textbook of medical physiology 12 edition page number:353,354,355