This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'Pulmonary function changes in acute bronchial asthma in untreated patient -a) ↑ed peak expiratory flowb)  ↓ed TLCc)  ↓ed FVC  d) ↑ed RVe) ↑ed FEV \nSelect and explain. \nA. ab, B. bc, C. cd, D. ac', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]