Identify the correct reagents that would bring about the following...

Options

1. A(i) $\mathrm{BH}_3$ (ii) $\mathrm{H}_2 \mathrm{O}_2 / \stackrel{\ominus}{\mathrm{O}} \mathrm{H}$ (iii) PCC
2. B(i) $\mathrm{BH}_3$ (ii) $\mathrm{H}_2 \mathrm{O}_2 / \stackrel{\ominus}{\mathrm{O}} \mathrm{H}$ (iii) alk. $\mathrm{KMnO}_4$ (iv) $\mathrm{H}_3 \mathrm{O}^{\oplus}$
3. C(i) $\mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}$ (ii) PCC
4. D(i) $\mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}$ (ii) $\mathrm{CrO}_3$