This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and Errors of Refraction, Subject name: Ophthalmology
[{'content': 'Prescription of presbyopic lens to a 50 year old emmetropic individual? \nSelect and explain. \nA. +0.50 D, B. +1.00 D, C. +1.50 D, D. +1.75 D', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A rough estimate of the power of presbyopic glasses in an emmetrope can be made from the age as follows:- 40 years: +1.00 DS 45 years: +1.25 DS 50 years: +1.75 DS 55 years: +2.00 DS 60 years: +2.25 DS 65 years and above: +2.50 DS', 'role': 'assistant'}]