This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Development period- week 1,2,3,4, Subject name: Anatomy
[{'content': 'The specialized group of mesenchymal cells that aggregate to form blood islands centrally and primitive blood vessels peripherally are called \nSelect and explain. \nA. Fibroblasts, B. Angioblasts, C. Cardiac progenitor cells, D. Myoblasts', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The angioblasts are the mesenchymal cells that form blood vessels in embryonic development, as well as embryonic blood cells.', 'role': 'assistant'}]