On reductive ozonolysis yields:

The correct order of reactivity of $\mathrm{PhMgBr}$ with

$\text{ (i) }{\left({\mathrm{C}}_6{\mathrm{H}}_5\right)}_2\mathrm{C}=\mathrm{O}$

$\text{ (ii) }{\left({\mathrm{CH}}_3\right)}_2\mathrm{C}=\mathrm{O}$

$\text{ (iii) }{\mathrm{CH}}_3-\mathrm{CH}=\mathrm{O}$