Match List I with List II. List I (compound): (1) $\mathrm{HgS}$ (2) $\mathrm{PbS}$ (3) $\mathrm{ZnCO}{}_3$ (4) $\mathrm{Fe}{}_2\mathrm{O}{}_3$. List II (treatment): (P) calcined, then the oxide is reduced with coke near 1673 K (Q) heating in air liberates the metal directly (R) partly roasted, then the oxide formed reacts with the remaining sulphide giving the metal (S) charged with coke, limestone and a hot air blast.

1. A1-Q, 2-R, 3-P, 4-S
2. B1-P, 2-R, 3-Q, 4-S
3. C1-Q, 2-R, 3-S, 4-P
4. D1-R, 2-Q, 3-P, 4-S