Concept:We use the identity a2−b2=(a+b)(a−b) after rearranging the given expression as a perfect square minus another square.Explanation:Start with x4+x2+1. Add and subtract x2 to complete a square: x4+2x2+1−x2. The first three terms form (x2+1)2, giving (x2+1)2−x2. Now apply the difference of squares: [(x2+1)−x][(x2+1)+x]. This simplifies to (x2−x+1)(x2+x+1). Thus, one factor is x2−x+1.Answer:Option C: x2−x+1