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': 'Apt presents with engorged neck veins, BP 80/50 and pulse rate of 100 following blunt trauma to the chest : Diagnosis is - \nSelect and explain. \nA. Pneumothorax, B. Right ventricular failure, C. Cardiac tamponade, D. Hemothorax', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]