Concept:Rusting destroys iron, so the metal loses its useful properties.Explanation:Rusting forms flaky iron oxide which weakens the iron.I. Loss of strength is caused by rusting.II. Loss of structure is caused by rusting because the metal crumbles away.III. Loss of electrical conductivity is also caused because rust is a poor conductor and damages the metal surface.Therefore, all three effects are caused by rusting.Answer:D. I, II and III