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
All except one are tests for macular function? 
Select and explain. 
A. Laser interferometry, B. Two point discrimination, C. Maddox rod test, D. Retinal ERG Electroretinogram
D: Retinal ERG Electroretinogram
Answer: D: Retinal ERG Electroretinogram 
Explanation: D i.e. Retinal ERG