From the following identify pairs in which metal is correctly matched with its refining process:
Understanding each metal's refining process:
A. Zn - Distillation: Zinc is refined by distillation due to its low boiling point, separating it from impurities with higher boiling points.
B. Sn - Liquation: Tin is refined using liquation, where impurities with different melting points are separated by heating the metal.
C. Ga - Zone refining: Gallium is refined by zone refining, where a molten zone moves along the metal, effectively purifying it by removing impurities.
D. Zr - Vapour phase refining: Zirconium is refined using vapour phase refining, where it reacts with chlorine to form ZrCl4, which is then distilled. Thus, all the given pairs are correct.