A student is given an unknown aqueous solution that contains either the divalent ion or trivalent ion of a certain metal (that is, the solution either contains metal(II) ions or metal(III) ions of the same metal). The student was also given a dilute solution of potassium permanganate which had a vivid purple color. Which of the following might be an appropriate way to ascertain which unknown solution the student was given?

A. Addition of the permanganate solution to the unknown solution would colorimetrically indicate whether metal(III) is reduced to metal(II). If the unknown solution contained the metal(III) ion, the purple color of the solution would get darker. If the unknown contained the metal(II) ion, the purple color of the solution would remain the same.

B. Addition of the permanganate solution to the unknown solution would colorimetrically indicate whether metal(II) is oxidized to metal(III). If the unknown solution contained the metal(II) ion, the purple color of the solution would get paler. If the unknown contained the metal(III) ion, the purple color of the solution would remain the same.

C. Addition of the permanganate solution to the unknown solution would colorimetrically indicate whether metal(III) is reduced to metal(II). If the unknown contained the metal(III) ion, the purple color of the solution would get paler. If the unknown contained the metal(II) ion, the purple color of the solution would get darker.

D. Addition of the permanganate solution to the unknown solution would colorimetrically indicate whether metal(II) is oxidized to metal(III). If the unknown solution contained the metal(II) ion, the purple color of the solution would get darker. If the unknown contained the metal(III) ion, the purple color of the solution would remain the same.

E. Addition of the permanganate solution to the unknown solution would colorimetrically indicate whether metal(II) is oxidized to metal(III). If the unknown solution contained the metal(III) ion, the purple color of the solution would get paler. If the unknown contained the metal(II) ion, the purple color of the solution would remain the same.