This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Ear, Subject name: ENT
[{'content': "What is sade's grade when tympanic membrane is retracted touching promontory \nSelect and explain. \nA. 1, B. 2, C. 3, D. 4", 'role': 'user'}, {'content': "Answer: C \nExplanation: Retraction of Pars Tensa (Sade's classification) Grade 1: Mild retraction not touching the long process of the incus. Grade 2: Retracted drum touching the long process of the incus. Grade 3: Retracted drum touching the promontory. It is also called as middle ear atelectasis. Grade 4: Drum plastered on the promontory. It is also called as adhesive otitis media. (Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 79)", 'role': 'assistant'}]