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
All are true about the trigone on the base of the urinary bladder, except: 
Select and explain. 
A. Mucosa is loosely associated to the underlying musculature, B. Mucosa is smooth, C. It is lined by transitional epithelium, D. It is derived from the absorbed pa of the mesonephric duct
A: Mucosa is loosely associated to the underlying musculature
Answer: A: Mucosa is loosely associated to the underlying musculature 
Explanation: Trigone of the urinary bladder is a small triangular area located at the base of the bladder with apex towards the lower side. The mucosa is firmly attached to the underlying musculature giving it a smooth texture.Ref: Human Anatomy, B D Chaurasia, 4th Edition, Volume 2, Chapter 30, Page 347; Clinical Anatomy by Regions, Richard S. Snell, 9th Edition, Chapter 7, Page 272.