Given:
One of the ways you can get the black cancel to the red one is by reflecting it over the y-axis
A way to imagine this is you paint the circle on the bottom left with black paint on some paper but then you fold the paper vertically and the paint sticks on the opposite side creating a mirrored cancel sign.
The second way to do this is simply by rotating the figure 90 degrees counterclockwise.
Answer:
Reflecting over the y axis or rotating it by 90 degrees counterclockwise.