The triangle has the following coordinates: (-6,1); (-4,1); (-6,6)
We want to know the coordinates of the preimage triangle reflected over the y-axis.
In this case, this triangle will have the same y-coordinates and the same distance form y-axis. But it's x-coordinates will be modified by a -1 factor.
Therefore, here's the new coordinates: (6,1); (4,1); (6,6) (option d)