The addition of magnesium chloride to the solution results in unaffected chemical equilibrium of the system. Thus, option A is correct.
The given chemical equation has been:
The reaction is reversible and can be converted back to the reactant with the increase in the product concentration. The equilibrium has been the condition when the concentration of products and reactants in the reaction are equal.
With an increase in products or reactants, there has been a corresponding chemical shift in the equilibrium.
The addition of Magnesium chloride in the solution, results in the dissociation of compound as:
The compound results in neither the increase of reactants, nor increase of product concentration in the acetic acid equilibrium.
Thus, the equilibrium of the system will remain unaffected by the addition of magnesium chloride. Thus, option A is correct.
For more information about equilibrium shift, refer to the link: