Which of the following regarding countercurrent exchange is false? select one: a. heat flow does not cease when temperatures nearly equalize. b. liquid cools while moving in one direction and warms by moving in the opposite direction c. countercurrent heat exchange occurs only when the opposite flow of adjacent fluid maximizes heat transfer. d. the blue fin tuna employs countercurrent exchange by taking in cold water through the mouth and into the gills, which in turn keeps the orga roughly the same temperature as the water.