Answer:
dilation by a factor of 1/3 about the origin
Step-by-step explanation:
Each side of triangle B is 1/3 the length of the corresponding side of triangle A. This tells you dilation using a scale factor of 1/3 is involved.
Lines joining corresponding points of triangles A and B converge on the origin. This tells you the center of dilation is the origin.
The one transformation that maps A to B is ...
dilation by a factor of 1/3 about the origin
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Additional comment
No rotation, reflection, or translation are needed, since the triangles have the same orientation, and dilation fully accounts for their relative position.
