Which role of water is significant for most living things in a biological system? a. it prevents many life processes from occurring. b. it slows down the transportation of nutrients. c. it provides temperature regulation. d. it does not freeze in cells at very cold temperatures.

I am pretty sure the correct answer is C.  Water has large heat capacity meaning it can absorb a lot of energy before changing temperature.  That helps the body regulate heat since it can be exposed to different environments and experience small temperature changes.

I hope this helps.  Let me know if anything is unclear.