Final answer:
The transformation T from R³ to R⁶ is not a rigid transformation because it does not preserve the angle between vectors in R³.
Step-by-step explanation:
The correct answer is D) The transformation T preserves the Euclidean distance but not the angle between vectors in R³.
A rigid transformation is a transformation that preserves distance and angle. In other words, if a transformation is rigid, the distance between any two points will remain the same, and the angle between any two vectors will remain the same. However, in this case, the transformation T only preserves the distance between points in R³, but it does not preserve the angle between vectors. Therefore, it is not a rigid transformation.