The choice of purification method depends on the physical states and properties of the components. Here both substances are liquids, are completely miscible, and have boiling points that differ but are reasonably close, at 78 and 110 degrees Celsius. Fractional distillation is designed exactly for such miscible liquid mixtures with moderately differing boiling points; the fractionating column provides repeated vaporisation and condensation cycles, enriching the vapour in the more volatile component at each stage and achieving clean separation. Option Simple sublimation is wrong because neither component is a solid that passes directly from solid to vapour. Option Crystallisation is incorrect because it purifies solids from solution, not miscible liquids. Option Steam distillation is unsuitable here because it applies to water-immiscible, steam-volatile substances, whereas these liquids are miscible with each other and there is no indication of steam volatility. This selection logic follows the NCERT framework for matching technique to mixture type. Plausibility check: a boiling-point gap of about 32 degrees is too small for a single simple distillation to separate cleanly, so the multistage action of a fractionating column is the appropriate choice.