This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy, Development and clinical examination, Subject name: Ophthalmology
[{'content': 'A wave in ERG is due to the activity of \nSelect and explain. \nA. Pigmented epithelium, B. Rods and cones, C. Ganglion cell, D. Bipolar cell', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Normal record of ERG consists of the following waves : a-wave. It is a negative wave possibly arising from the rods and cones. b-wave. It is a large positive wave which is generated by Muller cells but represents the activity of the bipolar cells. c-wave. It is also a positive wave representing the metabolic activity of pigment epithelium. Both scotopic and photopic responses can be elicited in ERG. Foveal ERG can provide information about the macula. REFERENCE : AK KHURANA COMPREHENSIVE OPHTHALMOLOGY, Edition4,Page-489', 'role': 'assistant'}]