This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Special Senses, Subject name: Physiology
[{'content': 'Total dioptric power of the crystalline lens inside the eye is: \nSelect and explain. \nA. 41 D, B. 18 D, C. 59 D, D. 72 D', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Diopteric power of the crystalline lens is +18 D. Total refractive power of the entire eye is +59 D; most of the refraction occurs at the anterior surface of the cornea (41 D).', 'role': 'assistant'}]