$\begin{array}{l}\mathrm{A}+\dot{\mathrm{CH}}_{3} \mathrm{MgI} \xrightarrow{\mathrm{H}^{+} / \mathrm{H}_{2} \mathrm{O}} \mathrm{X}\left(1^{\circ}\right) \\ \mathrm{B}+\mathrm{CH}_{3} \mathrm{MgI} \xrightarrow{\mathrm{H}^{+} / \mathrm{H}_{2} \mathrm{O}} Y\left(2^{\circ}\right) \\ \mathrm{C}+\mathrm{CH}_{3} \mathrm{MgI} \xrightarrow{\mathrm{H}^{+} / \mathrm{H}_{2} \mathrm{O}} \mathrm{Z}\left(3^{\circ}\right)\end{array}$