Circulatory systems compensate for
a. the need to cushion animals from trauma
b. temperature differences between the lungs and the active tissue
c. the slow rate at which diffusion occurs over large distances
d. the problem of communication systems involving only the nervous system

The slow rate at which diffusion occurs over large distances.

Explanation:

Circulatory system may be defined as one of the most important system of the body that contains arteries and veins. Two main types of circulatory system are open circulatory system and closed circulatory system.

The blood flow all over the body to each cell with the help of the circulatory system. Arteries carry oxygenated blood and veins carry deoxygenated blood in the body. The circulatory system increases the rate of blood flow as diffusion do not allow the transport at long distances.

Thus, the correct answer is option (c).