Answer:
The picture that shows a proper reflection across the red dashed line is figure B
Step-by-step explanation:
Given the figure in the attached image, we want to determine the picture that shows a proper reflection across the red line.
We can observe that for the figure A, the dimension of the preimage and the image are not the same. So, figure A does not show a proper reflection across the red dash line.
For figure B, the dimension and shape of the preimage is the the same as the image (they are congruent).
Therefore, The picture that shows a proper reflection across the red dashed line is figure B