A square piece of paper is folded as shown by the dotted line and the arrow, and the folded paper is punched as shown in the last figure. Choose the figure that shows the paper when it is unfolded.

Answer & explanation
Correct answer: option 4
The correct answer is Option (4) →

When a folded sheet is opened, every hole is repeated as its mirror image across each fold line, the last fold being opened first. Here the left half is folded over onto the right half, so opening it copies the hole across the vertical fold line. So the opened sheet has 2 holes, placed symmetrically about the fold line.

Option (1) — Incorrect. It shows only the holes as punched; their copies across the vertical fold line are missing.
Option (2) — Incorrect. The holes have been copied across the horizontal fold line instead of the vertical fold line, so they are in the wrong places.
Option (3) — Incorrect. It has an extra hole: the opened sheet has 2 holes, this option shows 3 holes.