The top half of a square sheet is folded down, and then the right half is folded over to the left. A triangle pointing up and a round hole are punched. Which figure shows the sheet opened out?

Undo the last fold first: mirroring across the upright crease copies the holes to the right, triangles still pointing up. Then mirroring across the flat crease copies everything to the top half, where the triangles point down: (d).