This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of orbit, Lids and lacrimal apparatus, Subject name: Ophthalmology
[{'content': 'Upper Lid Retractors include? \nSelect and explain. \nA. Muller muscle and superior rectus, B. Levator palpabrae superioris and superior oblique, C. Superior oblique and superior rectus, D. Levator palpebrae superioris & muller muscle', 'role': 'user'}, {'content': "Answer: D \nExplanation: *The levator palpebrae superioris is the impoant upper eye lid retractor. Injury or weakness to this muscle leads to ptosis. *Deep pa of the elevator muscle is the Muller's muscle, which is sympathetically innveed. Ref: Textbook of Ophthalmic reconstructive surgeries p.786", 'role': 'assistant'}]