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: ENT
[{'content': "Dysfunction of tympanic membrane is characterized by all except - \nSelect and explain. \nA. Normal 'cone of light', B. Retracted TM, C. Nonprominent umbo, D. Fullness in middle ear", 'role': 'user'}, {'content': 'Answer: A \nExplanation: Retracted Tympanic Bembrane\nIt is the result of negative intratympanic pressure when Eustachian tube is blocked\nCharacteristics\n\nIt appears dull and lusterlessQ\nCone of light is absent or interruptedQ\nHandel of malleus appears foreshortened Q\nLateral process of malleus becomes more prominent Q\nAnterior and posterior malleal folds become sickle shaped Q\nIt is immobile or has limited mobility when tested with pneumatic otoscope or siegle’s speculum.\n\nFeatures of Normal Tympanic Membrane\n\nIt is shiny and pearly grey in colour\nHas concavity on its lateral surface\nCone of light seen in antero – inferior quadrant\nIt’s transparency varies\nIt is mobile when tested with pneumatic otoscope or siegle’s speculum.', 'role': 'assistant'}]