Water flowing over gills and blood flowing through gill capillaries moving in opposite directions is called .
a. capillary respiration
b. out pouching exchange
c. anaerobic respiration
d. countercurrent exchange
e. lactate respiration

D.) Countercurrent exchange

Explanation:

Countercurrent exchange is the exchange of substances between two fluids moving in opposite directions, so this would be the most reasonable response.

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .