All of the following are functions of water, except:

Assuming that your talking about the functions of water in our body, 

Regulating Calcium deposits in bones IS NOT one of them.

A couple of water's functions in our body are :
- body cooling
- it maintain our blood volume
- it lubricate our tissue

Your answer is  d.)relationship between pressure and air volume and led to the understanding of how respiration works

Not sure exactly what kind of answer you are looking for so i hope this able to be a effective listener and also being  a good conversationalist. and most of all just being there when someone needs you.i hope this .