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': 'Which of the following sinuses is the first one to develop \nSelect and explain. \nA. Frontal, B. Maxillary, C. Sphenoid, D. Ethmoid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Maxillary sinus is first to develop. It appears as a shallow groove on the medial surface of maxilla during fourth month of intrauterine life, grows rapidly during six to seven years, and reaches full the eruption after all permanent teeth erupts.', 'role': 'assistant'}]