This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oral Cavity, Subject name: Surgery
[{'content': 'The most common cyst of the oral region is - \nSelect and explain. \nA. Dentigerous cyst, B. Keratosis cyst, C. Dermoid cyst, D. Periapical cyst', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) Periapical cystRef: Scott-Browns Otorhinolaryngology 7/e p 1924-1925Periapical Cyst (Radicular Cyst)* MC type of Jaw cyst* Inflammatory origin* Found at the apex of teeth.* Result in long standing Pulpitis.* Removal of irritant material and tooth extraction.', 'role': 'assistant'}]