When hydrogen peroxide (H2O2) is added to potassium iodide (KI) solution, the hydrogen peroxide decomposes into water (H2O) and oxygen (O2). The chemical equation for this decomposition reaction is: 2H2O2 → 2H2O + O2

In this reaction, the potassium iodide is needed for the reaction to happen, but it isn’t changed in the reaction and can be used again. What is the role of potassium iodide in this reaction?

A. Reactant

B. Product

C. Precipitate

D. Catalyst