This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal physiology, Subject name: Physiology
[{'content': 'Relaxation of mesangial cells is responsible for \nSelect and explain. \nA. Absorption of glucose, B. Maintenance of blood flow, C. Osmotic gradient in medulla, D. Secretion of uric acid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Mesangial cells are specialized cells around blood vessels in the kidneys, at the mesangium. They are specialized smooth muscle cells that function to regulate blood flow through the capillaries,Ref: Ganong&;s review of medical physiology; 24th edition; page no: 673', 'role': 'assistant'}]