Final answer:
Iodine, being less reactive than bromine, can be part of a single replacement reaction, where the brown color indicates the formation of iodine.Option D is the correct answer.
Step-by-step explanation:
Based on the data provided, the conclusion that can be made about the chemical reaction is that iodine is less reactive than bromine. Iodine, being the least reactive of the halogens, is the weakest oxidizing agent and requires heating to react with metals. It does not oxidize other halide ions. According to the reactivity series of halogens, an element can only replace another element below it in the halogen group. Since iodine is below bromine on the periodic table, iodine will not replace bromine in a single replacement reaction. Thus, Potassium iodide and bromine do react, and the color change to deep brown indicates the formation of iodine from the single replacement reaction.