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
[{'content': "Urachus is the remnant of \nSelect and explain. \nA. Allantois, B. Meckel's diveiculum, C. Umbilcal aery, D. Left umbilical vein", 'role': 'user'}, {'content': 'Answer: A \nExplanation: xThe developing bladder is continuous cranially with the allantois.it is unceain whether the allantois contributes to the formation of the bladder .the allantois atrophies and is seen in postnatal life as a fibrous band the urachus extending from the apex of bladder to umbilicus Ref Human embryology Inderbier Singh Tenth edition Page no 292', 'role': 'assistant'}]