This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Epithelium of "Trigone of bladder" is derived from 
Select and explain. 
A. Vesicourethral Canal, B. Mesoderm, C. Splanchnopleuric Mesoderm, D. Urachus
B: Mesoderm
Answer: B: Mesoderm 
Explanation: The urinary bladder is derived from the cranial pa of the vesicourethral canal (endoderm).The epithelium of the trigone is derived from absorbed mesonephric ducts (mesoderm)Reference: Inderbir Singh Embryology; 10th edition; Page no: 292