Which figure shows the opened sheet if a square sheet is folded once along its other diagonal, the top-left half going over the bottom-right half, and then punched twice?

The crease runs from the top-right corner to the bottom-left corner. Each hole is mirrored across it: the hole near the right edge gets a twin near the top edge, and the hole near the bottom edge gets a twin near the left edge. That is (d).