Final answer:
The correct answer is C. An increase in mean arterial pressure will increase flow into tissue capillaries.
Step-by-step explanation:
The correct answer to the question is C. An increase in mean arterial pressure will increase flow. Mean arterial pressure is the average pressure in the arterial system, which drives blood flow into the tissues. An increase in mean arterial pressure will result in increased flow into tissue capillaries, whereas vasoconstriction of the arterioles (option A) will decrease flow. An increase in arteriolar resistance (option B) and a smaller radius of the arteriole (option D) will both increase resistance and decrease flow.