The correct answer is AlCl3 + 3H2O ? Al(OH)3 + 3HCl.Explanation:Redox reactions involve the oxidation and reduction of reacting species at the same time. Thus, a change in oxidation state determines whether or not a reaction is redox.An oxidising agent (also oxidant) is the element or compound that accepts an electron from another species in an oxidation-reduction (redox) reaction. Because the oxidising agent is gaining electrons (and thus is frequently referred to as an electron acceptor), it is said to be reduced.During a redox reaction, a reductant is a reactant that donates electrons to other reactants.AlCl3 + 3H2O ? Al(OH)3 + 3HCl is not an example of a redox reaction because in this reaction oxidation and the reduction do not take place.Additional Information2NaH ? 2Na + H2 oxidation reduction 4Fe + 3O2 ? 2Fe2O3 oxidation reduction CuSO4 + Zn ? Cu + ZnSO4 reduction oxidationThus, the above 3 reactions are an example of redox reactions because in these reactions oxidation and reduction take place simultaneously.