What is the most abundant and most important inorganic compound in the body?

The correct answer is water. Since carbon is the common element of organic compounds, the molecule of an organic material must have at least one carbon atom in its molecule. Water does not contain any carbon atom in its molecule, H2O. So water is only an inorganic compound. It is the most abundant and important inorganic compound in living material. It makes up about 60-80% of the volume of most living cells.