The correct answer is "Odilation."
1. **Reflection:** An isometry that flips or mirrors an object over a line is a reflection. For example, when you look at yourself in a mirror, the reflection you see is a result of a reflection isometry.
2. **Rotation:** An isometry that involves turning or spinning an object around a fixed point is a rotation. Imagine turning a piece of paper around a pencil tip; the resulting movement is a rotation isometry.
3. **Translation:** An isometry that slides an object in a certain direction without changing its orientation is a translation. For instance, shifting a book along a desk without flipping or rotating it is a translation isometry.
4. **Dilation:** Dilation is not an isometry because it involves changing the size of an object by stretching or compressing it. Unlike reflections, rotations, and translations that preserve shape and size, dilation alters the scale of an object, making it not qualify as an isometry.
Therefore, among the options provided, "Dilation" is the one that is not considered an isometry.
