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: Pathology
[{'content': 'Mucous retention cysts are most commonly found on: \nSelect and explain. \nA. Lower lip, B. Floor of the mouth, C. Buccal mucosa, D. All of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: Mucous retention cysts are more commonly found on the lower lip, the ﬂoor of the mouth and buccal\xa0mucosa. The pooled up saliva causes dilation of the duct and development of an aneurysm-like lesion\xa0lined by epithelium.\nThe retention phenomenon involving accessory salivary gland structures occurs most frequently on the lower lip, but may also occur on the palate, cheek, tongue (involving the glands of Blandin-Nuhn), and floor of the mouth.\nRef: Shafer's textbook of oral pathology 7th edition page 543", 'role': 'assistant'}]