In Clemmensen's reduction, acetone gives ________.

The reactivity order of the following compounds with ${\mathrm{CH}}_3\mathrm{MgBr}$ is:

$\text{(i) }{\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}$

$\text{(ii) }{\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COCl}$

$\text{(iii) }{\mathrm{CH}}_3{\mathrm{COOCH}}_3$

$\text{(iv) }{\mathrm{CH}}_3{\mathrm{COOCOCH}}_3$

$\left(\mathrm{i}\right)$ 

$\left(\mathrm{ii}\right)$ 

$\mathrm{A}$ and $\mathrm{B}$ are, respectively,:

In the following reaction, the reagent $\mathrm{Z}$ can be

Pent$-4-\mathrm{en}-2$one$\stackrel{\mathrm{Reagent}-\mathrm{Z}}{\to }$Pentan$-2-\mathrm{ol}$