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': 'Excessive bleeding during hemothorax is caused usually by- \nSelect and explain. \nA. Vena cava, B. Internal mammary artery, C. Heart, D. Major artery', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Massive Hemothorax:\n\nCollection of more than 1500 ml of blood in the pleural cavity is called massive hemothorax.\nMassive hemothorax is usually the result of major pulmonary vascular injuries or major arterial wounds, while minor lung injuries cause small hemothorax.\n\nAlso know \n\nMost common cause of hemothorax is due to injuries of Internal mammary Artery.', 'role': 'assistant'}]