This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and PNS, Subject name: ENT
[{'content': 'Most superior sinus in the face is? \nSelect and explain. \nA. Frontal sinus, B. Ethmoid sinus, C. Maxillary sinus, D. Sphenoid sinus', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) Frontal sinusRef: Gray's Basic Anatomy 40th ed p 562", 'role': 'assistant'}]