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
[{'content': 'In hyperventilation \nSelect and explain. \nA. P50 and Hb affinity for O2 increases, B. P50 and Hb affinity for O2 decreases, C. P50 increases and affinity O2 decreases, D. P50 decreases and affinity O2 increases', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Abnormally fast and deep breathing, the result of either an emotional state or a physiological condition. Emotional causes include acute anxiety and emotional tension, such as in nervous, anxious patients who may have other functional disturbances related to emotional problems. Physiological causes include a rapid decrease in intracranial pressure, other neurologic problems, and metabolic, pulmonary, and cardiovascular conditions.Ref: Ganong&;s Review of Medical Physiology; 24th edition; page no:647', 'role': 'assistant'}]