Which method separates colours in ink?

Correct answer: Paper chromatography

The direct answer is A: paper chromatography. Chromatography separates substances because different components dissolve in a moving solvent to different extents and travel at different speeds. To separate ink, a small spot is placed on paper; the lower edge of the paper is put in a suitable solvent; the solvent rises through the paper; different dyes move different distances and appear as separate coloured spots. Option A is correct. Option B, simple distillation, is mainly used to separate a liquid from dissolved non-volatile material or liquids with a suitable boiling-point difference, not normally to display the several dyes in ink. Option C, sublimation, is used when a solid changes directly into vapour, so it is not the usual method for ink colours. Option D, filtration, separates insoluble solid particles from a liquid; dissolved dyes pass through the filter. Remember: a moving solvent carrying different colours through paper means chromatography.