The major products $P$ and $Q$ formed in the following reactions schemes are

The major aromatic product of the following reaction sequence is

The order of reactivity of the following compounds towards the esterification with acetic acid is

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