This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Embryology 2, Subject name: Anatomy
[{'content': 'The lateral mesoderm is divided into two distinct layers by the formation of the \nSelect and explain. \nA. Extraembryonic coelom, B. Intraembryonic coelom, C. Cardiogenic region, D. Notochord', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The lateral mesoderm is a subdivision of intraembryonic mesoderm and initially is a solid plate of mesoderm. The intraembryonic coelom forms in the middle of the lateral mesoderm, thereby dividing it into the intraembryonic somatic mesoderm and intraembryonic visceral mesoderm.', 'role': 'assistant'}]