Circulatory systems have the primary benefit of overcoming the ...

[luvbio]

Circulatory systems have the primary benefit of overcoming the shortcomings of
A)  temperature differences between the lungs and the active tissue.
B)  the slow rate at which diffusion occurs across cells.
C)  communication systems involving only the nervous system.
D)  having to cushion animals from trauma.
E)  fetal organisms maintaining an optimal body temperature.

[coco]

Choose B

GL