${\mathrm{H}}_2\mathrm{COH}.{\mathrm{CH}}_2\mathrm{OH}$ on heating with periodic acid, gives

Following compounds are given:

$\left(\mathrm{i}\right)$ ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}$ $\left(\mathrm{ii}\right)$ ${\mathrm{CH}}_3{\mathrm{COCH}}_3$ $\left(\mathrm{iii}\right)$  $\left(\mathrm{iv}\right)$ ${\mathrm{CH}}_3\mathrm{OH}$

Which of the following can show iodoform reaction?

The Clemmensen reduction of a ketone is carried out in the presence of which of the following ?

The order of the reactivity of phenyl magnesium bromide $\left(\mathrm{PhMgBr}\right)$ with the following compounds :

The above reaction is :