In the Reaction Below, Which Species Will Not Be Written $\rightarrow$

Multiple Choice

In the reaction below, which species will not be written as its constituent ions when the equation is expanded into the ionic equation?
Mg(OH) ₂ (s) + 2HCl (aq) $\rightarrow$ MgCl₂ (aq) + 2H₂O (l)

A) HCl
B) MgCl₂
C) Mg(OH) ₂ only
D) H₂O and Mg(OH) ₂