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': 'In a patient with previous history of congestive cardiac failure, during dental treatment if he shows sign and symptoms. The preferable patient position should be: \nSelect and explain. \nA. Trendelenberg position, B. Upright position, C. Reverse trendelenberg position, D. Left lateral position', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]