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: Physiology
[{'content': 'In laminar flow, if diameter is reduced to half ? \nSelect and explain. \nA. Blood flow increases four fold, B. Blood flow decreases four fold, C. Blood flow increases sixteen-fold, D. Blood flow decreases sixteen-fold', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Blood flow decreases sixteen-foldIf everything else remains constant, blood flow is direactly poropoional to 4th power of radius.Thus, if the diameter (or radius) is reduced to half, blood flow will decrease sixteen-fold.", 'role': 'assistant'}]