Sustained exercise can increase the blood flow rate of the heart by a factor of five with only a modest increase in blood pressure. This is a large change in flow. Although several factors come into play, which of the following physiological changes would most plausibly account for such a large increase in flow with a small change in pressure?

A. A decrease in the viscosity of the blood
B. Dilation of the smaller blood vessels to larger diameters
C. Dilation of the aorta to larger diameter
D. An increase in the oxygen carried by the blood

B

Explanation: During exercise, smaller blood vessels responsible for the flow of blood in the body dilate to allow increased flow of blood with little pressure. The dilated vessels increase blood flows which allows for the circulation of oxygenated blood to the muscles.

B. Dilation of the smaller blood vessels to larger diameters

Explanation:

thermal energy is the answer

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.