2. which type of isometry is the equivalent of two reflections across two vertical lines? a. translation b. rotation c. glide reflection d. none of these.

Translation

One reflection moves the figure some distance, and everything is mirrored. Another reflection along a line parallel to the original mirroring line will move the figure even further and the image will flip back to the original orientation. Overall, the figure will translate (ie slide or shift) along the perpendicular direction of the mirroring lines. The lines must be parallel. In this case, all vertical lines are parallel so that condition is met.