Concept:This equation shows the essential ionic change that occurs when an acid reacts with a base.Explanation:The reaction combines H+ ions, from an acid, with OH− ions, from a base, to produce H2O.This process is called neutralization.No solid precipitate is formed, so precipitation is not correct.Hydration and hydrolysis do not describe the simple combination of H+ and OH− to form water.Answer:D. neutralization