Concept:Recognize each quadratic as a perfect square trinomial: a2±2ab+b2=(a±b)2.Explanation:First, factor x2−14x+49. Notice it matches (x)2−2(x)(7)+72, so it equals (x−7)2.Next, factor x2+6x+9. It matches (x)2+2(x)(3)+32, so it equals (x+3)2.The given expression is the product of these two squares: (x−7)2(x+3)2.Take the square root of the whole product: (x−7)2(x+3)2=(x−7)(x+3).Thus the square root simplifies directly to the product of the two binomials.Answer:A. (x−7)(x+3)