Which of the following decolourise cold, dilute, alkaline $\mathrm{KMnO}{}_4$ (Baeyer's reagent)? (more than one may be correct)

Baeyer's reagent is decolourised by unsaturated $\mathrm{C}=\mathrm{C}$ and $\mathrm{C}\equiv \mathrm{C}$ bonds (oxidation to diols or diketone/acid products), so propene and propyne are positive. Saturated cyclohexane and benzene, with its delocalised ring, are not oxidised under these mild conditions.