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
Surfers ear is 
Select and explain. 
A. Exostosis, B. Otosclerosis, C. Otitis externa, D. Squamous cell Carcinoma
A: Exostosis
Answer: A: Exostosis 
Explanation: Exostoses are multiple and bilateral, often presenting as smooth, sessile, bony swellings in the deeper pa of the meatus near the tympanic membrane. They arise from the compact bone. Exostosis is often seen in persons exposed to the entry of cold water in the meatus as in divers and swimmers. Hence called a surfers ear. Reference: Diseased of Ear, Nose and Throat, PL Dhingra, 7th edition, pg no.119