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: Medicine
[{'content': 'Sudden onset of cough followed by increased dyspnea is typical of- \nSelect and explain. \nA. Pneumothorax, B. Lobar pneumonia, C. Collapse of lung, D. Acute pleurisy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Causes of pneumothorax: 1. Primary spontaneous: a)rupture of apical blebs b)smokers 2.secondary : a)copd and any other lung disease 3. Traumatics secondary to thoracentesis,central intravenous catheters 4.tension pneumothorax: during mechanical ventilation may cause decreased venous return and decreased cardiac output.', 'role': 'assistant'}]