This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lens, Subject name: Ophthalmology
[{'content': 'What is the new advance in cataract surgery? \nSelect and explain. \nA. Femtosecond laser, B. Neodymium Laser, C. Nanosecond laser, D. Picosecond Laser', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Femtosecond laser * Femtosecond laser-assisted cataract surgery provides surgeons an exciting new option to potentially improve patient outcomes and safety.* In this surgery a femtosecond laser is used for various steps like lens fragmentation and capsulotomy.* Although the results have been good the technology is currently very expensive.", 'role': 'assistant'}]