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: Ophthalmology
[{'content': 'Process of dark adaptation involves: \nSelect and explain. \nA. Rods of retina, B. Cones of retina, C. Pigment epithelium of retina, D. Both rods and cones', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Both rods and cones', 'role': 'assistant'}]