Respuesta :
The term that name the water in a chemical reaction that water decomposes is.
reactant ( answer D)
Explanation
Reactant is a substance that take part in and undergoes change during a reaction. In other words reactant are consumed to form product.
water is reactant when it decomposes because it is consumed to form hydrogen and oxygen.
The decomposition of water is as below equation,
2H2O→ 2 H2 + O2