Concept:Use the difference of two squares identity: a2−b2=(a+b)(a−b).Explanation:The expression is (x+2)2−(2x+1)2.Let a=x+2 and b=2x+1.Then a2−b2=(a+b)(a−b).So, (x+2)2−(2x+1)2=[(x+2)+(2x+1)][(x+2)−(2x+1)].Simplify the first bracket: (x+2)+(2x+1)=3x+3.Simplify the second bracket: (x+2)−(2x+1)=x+2−2x−1=−x+1.Thus, the factorised form is (3x+3)(1−x).Factor out 3 from 3x+3: 3(x+1)(1−x).Answer:3(x+1)(1−x)Correct option: D.