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
Surgery preferred for severe ptosis with pool levator function 
Select and explain. 
A. Fasanella - servat, B. levator resection, C. Everbusch's operation, D. Frontalis sling
D: Frontalis sling
Answer: D: Frontalis sling 
Explanation: Frontalis sling - Tucking upperlid to frontalis muscle with the help of fascia lata or non - absorbable materials.