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: Anatomy
[{'content': 'Upper premolars are supplied by \nSelect and explain. \nA. Anterior superior alveolar, B. Middle superior alveolar, C. Posterior superior alveolar, D. Inferior alveolar', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]