Alcohol Phenols And Ethers

Reactions that produce $n$-butanol in the following are :

I. $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}=\mathrm{CH}_2 \xrightarrow[\text { (ii) } \mathrm{NaOH} / \mathrm{H}_2 \mathrm{O}_2]{\text { (i) } \mathrm{B}_2 \mathrm{H}_6}$

II. $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CHO} \xrightarrow[\text { (ii) } \mathrm{H}_2 \mathrm{O}]{\text { (i) } \mathrm{CH}_3 \mathrm{Mgl}}$

III. $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{CN} \xrightarrow[\substack{\text { (ii) } \mathrm{H}_3 \mathrm{O} \\ \text { (iii) } \mathrm{NaBH}_4}]{\text { (i) } \mathrm{SnCl}_2, \mathrm{HCl}}$

IV. $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{CO}_2 \mathrm{H} \xrightarrow{\mathrm{B}_2 \mathrm{H}_6}$