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': 'Which perforation of the tympanic membrane is most commonly seen with tubotympanic CSOM? \nSelect and explain. \nA. Central, B. Anterosuperior, C. Posterosuperior, D. Posteroinferior', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tubotympanic CSOMIt is also known as safe ear as it does not cause any serious complicationsInfection is limited to anteroinferior pa of middle ear cleft (eustachian tube & mesotympanum) and is associated with central perforation in pars tensa of the tympanic membraneRef: PL Dhingra, Diseases of Ear, Nose & Throat, 7th edition, pg no. 75', 'role': 'assistant'}]