3) What happens to the carbon in glucose or any other metabolized material? a. It becomes part of pyruvate and then lactic acid which is filtered by your blood.
b. It is broken down into its smallest form and expelled as carbon dioxide.
Carbon is broken down and used for energy leaving only H+ ions which eventually form
water
d. Both A and B are correct
e. All of the above
C.

It's either -limiting factors or -scarce resources but i'd go with my first answer since the food and water are abundant they really aren't scarce

Na+ loss through sweet plus the dilution has lowered na+ concentration outside of neurons, altering the na+ equilibrium potential. sodium exists more outside the cells than inside. when na+ is lost by sweat plus the dilution( because they drink a lot of water) changes the concentration outside the cell, forcing the water to enter the cell and attempt to balance the concentration inside/outside.the problem is that the abundance of water will cause the cells to swell. most cells can adapt, however, the brain cells can't that's why the runner has confusion and can't control the muscles.  if not treated and this occurs in less than 48 hours, it can be immediately fatal .