This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anaesthesia
[{'content': 'Percentage of tetracaine used in eye surgery \nSelect and explain. \nA. 0.50%, B. 1%, C. 2%, D. 4%', 'role': 'user'}, {'content': "Answer: A \nExplanation: Cataract surgery can be performed using topical anaesthesia alone. Tetracaine 0.5% and Lidocaine 4% can be used. Advantages of this method are that it avoids the potential complications with retrobulbar and peribulbar injections. Disadvantages include the potential for eye movement during surgery, increased patient anxiety, and discomfo from the microscope light.(Refer: stoelting's pharmacology and physiology in anaesthetic practice ,5th edition ,pg no.282-283)", 'role': 'assistant'}]