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: Anatomy
[{'content': 'All are true about trigone of bladder except: \nSelect and explain. \nA. Mucosa is loosely attached to the underlying musculature, B. Mucosa is smooth, C. Lined by transitional epithelium, D. Derived from absorbed pa of the mesonephric duct', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Mucosa loosely attached to the underlying musculature', 'role': 'assistant'}]