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': "Surgery preferred for severe ptosis with pool levator function \nSelect and explain. \nA. Fasanella - servat, B. levator resection, C. Everbusch's operation, D. Frontalis sling", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Frontalis sling - Tucking upperlid to frontalis muscle with the help of fascia lata or non - absorbable materials.', 'role': 'assistant'}]