This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Middle Ear (Otitis Media), Subject name: ENT
Retraction of tympanic membrane touching the promontory. It is called - 
Select and explain. 
A. Mild retraction, B. Severe retraction, C. Atelectasis, D. Adhesive otitis
C: Atelectasis
Answer: C: Atelectasis 
Explanation: Ans. is 'c' i.e., Atelectasis Sade's grading of Pars tensa retractionGradeTitleDescription1Retracted earSlight retraction of ear drum2Severe retractionRetracted drum touching the incus or stapes3AtelectasisTympanic membrane touching promontory4Adhesive otitisTympanic membrane adherent to promontory5 Spontaneous perforation of atelectatic ear drum with otorrhea & polyp formation