are substances found in foods that are not in a form directly usable by the body, but that can be converted into an active form once they are absorbed; however vitamins found in foods that are already in the active form, called vitamins, do not undergo conversion.

I Think part of the answer is provitamins and the second answer is  preformed

Explanation:

a. as the temperature increases, the kinetic energy of the gas molecules increases & the molecules move faster & further away from each other.

b. if you decrease the temperature of a fixed amount of gas at constant pressure, the combined gas law reduces to charles's law. in this case, volume will also decrease.

d is the answer

sorry if its wrong!