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
A wave in ERG is due to the activity of – 
Select and explain. 
A. Pigmented epithelium, B. Rods and cones, C. Ganglion cell, D. Bipolar cell
B: Rods and cones
Answer: B: Rods and cones 
Explanation: Waves in ERG are :


Negative 'a' wave represent the activity in rods and cones.
Positive 'b' wave arises in inner retinal layers.
Positive 'c' wave is associated with the pigmentary epithelium.