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: Surgery
[{'content': 'Which of the following is likely to cause obstructive shock? \nSelect and explain. \nA. Myocardial infarction, B. Dysrhythmia, C. Tension pneumothorax, D. Valvular heart disease', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Common causes of obstructive shock include cardiac tamponade, tension pneumothorax, massive pulmonary embolus and air embolus.', 'role': 'assistant'}]