The answer is starch because iodine reacts with starch to change the colour to inky blue or black.
All the others are present in milk naturally so I’m assuming they intent starch
<span>According to Georgia Perimeter College, </span>tap water<span> is not </span>heterogeneous.Heterogeneous mixtures<span> have at least two substances, and viewers can see what is in it. </span>Tap water<span> is </span>homogeneous<span>, as </span>homogeneous mixtures<span> have at least two substances in them, but viewers cannot see them.</span>
gimme a sec im doing the quick check.