Which triangle results from a reflection across the line x = 1?

The correct answer is option D. Detailed explanation: As per the attached image. Observing the image, the coordinates are outlined. To determine the reflection of a point across a line, the distances from the points to the line must be equal. Point A(1,1) sits on the line x = 1, meaning its reflection A' remains at A'(1,1). Point C(2,5) is a distance of 1 from x = 1 on the right, hence its reflected position C' shifts left by the same distance — subtracting 1 from its x-coordinate places it at C'(1 - 1, 5) or C'(0, 5). Point B(4,1) is positioned 3 from x = 1 on the right; therefore, its reflection B' would also move left by 3 – leading to B'(1 - 3, 1) or B'(-2, 1). Plotting A', B', and C' confirms option D as the correct choice.

D