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': 'Features of superior vena cava syndrome are all except which of the following? \nSelect and explain. \nA. Facial swelling, B. Hoarseness, C. Aggravation of symptoms in sitting position, D. Syncope', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Answer- C. Aggravation of symptoms in sitting positionSuperior vena cava syndrome (SVCS) is the clinical manifestation of superior vena cava (SVC) obstruction, with severe reduction in venous return from the head, neck and upper extremities.Aggravating factors:Bending forward or lying down may aggravate the symptoms.', 'role': 'assistant'}]