A square sheet is folded with the top half down over the bottom half. A small rectangle is snipped off the bottom edge of the folded paper. Which figure shows the sheet after it is opened?

After this fold the bottom edge holds two edges of the sheet: its own bottom edge and, folded down onto it, its top edge. So the snip takes a notch from the middle of the bottom edge and a matching notch from the middle of the top edge: (d).