Which transformation is described as reflecting a figure through a line?

• A. Translation
• B. Axial symmetry
• C. Central symmetry
• D. Rotation

Answer: (B)

Reflecting a figure through a line is mirror reflection across that line, also called axial symmetry. In this transformation, every point moves to a mirror point on the opposite side of the line at the same perpendicular distance from the line. The line itself stays fixed, so points on the line do not move, and pairs of points equidistant from the line swap places. The image has the same size and shape as the original, just flipped like a mirror image. This is different from a translation (which shifts every point by the same vector with no fixed line), a rotation (which turns around a fixed center), or central symmetry (a 180-degree rotation about a point).