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: Radiology
[{'content': 'Emergency radiotherapy is given in \nSelect and explain. \nA. Superior vena cava syndrome, B. Pericardial temponade, C. Increased ICP, D. Spinal cord compression', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Note the swelling of his face first thing in the morning (left) and its resolution after being upright all day (right). Specialty. Pulmonology.\nSuperior vena cava syndrome (SVCS), is a group of symptoms caused by obstruction of the superior vena cava\n(a short, wide vessel carrying circulating blood into the heart).', 'role': 'assistant'}]