Identify ' X ' in the following reaction.

Grignard reagent carbon is nucleophilic or basic, there is no reaction between two nucleophiles
$\text{(}\overline{C}\text{and}\overline{OD}\text{).}$

the given substrate requires two equivalents of Mg.
(4) Reactivity order of RX to form Grignard reagent is;
$\mathrm{R}-\mathrm{I}>\mathrm{R}-\mathrm{Br}>\mathrm{R}-\mathrm{Cl}>\mathrm{R}-\mathrm{F}$