23Acid Base Properties ReactionsMedium1 markFour oxides are listed.calcium oxidecopper(II) oxidesulfur dioxidezinc oxideWhich statement about these oxides is correct?AAll of them contain oxide ions.BOnly three of them are reduced by carbon to give a metal.COnly two of them react with aqueous NaOH to give a salt.DOnly one of them will give a colour in the flame test.Grade answerGrading criteria