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': 'In a patient with senile cataract the macular functions can be tested by all except: \nSelect and explain. \nA. Two-light discrimination test, B. Swinging flash light test, C. Maddox rod test, D. Laser interferometry', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Swinging flash light test', 'role': 'assistant'}]