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': 'Spleen is derived from ? \nSelect and explain. \nA. Ventral mesogastrium, B. Dorsal mesogastrium, C. Septum transversorium, D. Allantois', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Dorsal mesogastrium', 'role': 'assistant'}]