Concept:Use BODMAS and change one operator so the expression becomes 0.Explanation:Original expression: 28−7+2×2.First solve multiplication: 2×2=4.Then 28−7+4=25, which is not 0.Change the + sign into ×.New expression: 28−7×2×2.Multiply: 7×2×2=28.Then 28−28=0.So the required change is + into ×.Answer:A. Change + into ×