Answer: Rotation
Explanation:
From the figure , we can observe that both figure A and b are absolutely congruent.
To translate a figure to make congruent images , we use rigid motions (Translation, Reflection, Rotation)
It is Rotation because of we move Figure A 180 degrees clockwise about the fixed point O, we will get Figure B .
It cannot be reflection because both figures are not mirror images.
It cannot be translation because all points on Figure A is not moving , as point O remained at same position throughout this which is not possible in translation.