How is the excretory system most likely to respond when an animal is thirsty?

a) By relaxing the smooth muscles

b) By retaining body fluids

c) By absorbing heat from lymph glands

d) By releasing hormones

The excretory system is most likely to respond when an animal is thirsty in this way: B. by retaining body fluids.

Because the body doesn't get enough fluids to not be thirsty anymore, it retains whatever fluids it already has in it until the thirst is satiated.