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: Pathology
[{'content': 'The cardinal sign of inflammation called rubor is mainly the result of: \nSelect and explain. \nA. Decreased interstitial hydrostatic pressure, B. Decreased vascular permeability of capillaries, C. Increased vascular permeability of venules, D. Vasodilation of arterioles', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Inflammation can be defined as the reaction of vascularized living tissue to local injury. Celsus originally described four cardinal signs of inflammation: rubor (redness), tumor (swelling), calor (heat), and dolor (pain). Virchow later added a fifth sign, loss of function (functio\xa0laesa). Redness (rubor) and heat (calor) are primarily the result of increased blood flow, secondary to vasodilation of arterioles.', 'role': 'assistant'}]