Arrange the average oxidation number of S in these species in INCREASING order: (i) $\mathrm{S}{}_2\mathrm{O}{}_3{}^{2-}$, (ii) $\mathrm{S}{}_4\mathrm{O}{}_6{}^{2-}$, (iii) $\mathrm{SO}{}_3{}^{2-}$, (iv) $\mathrm{S}{}_2\mathrm{O}{}_8{}^{2-}$ (one peroxo link, the two O-O oxygens at $-1$).

1. A(i), (ii), (iii), (iv)
2. B(ii), (i), (iii), (iv)
3. C(i), (iii), (ii), (iv)
4. D(iv), (iii), (ii), (i)