Note: The figures shown are representative.
C
Step-by-Step Solution
Key idea: Reverse unfolding using the reflection principle. We start from the final cut state and unfold step-by-step, mirroring the cuts across the fold lines.
Step 1: Analyze the final folded state (Figure IV). It is a right-angled triangle. The cuts are:
- A rectangular hole inside the triangle.
- A triangular notch on the top edge (hypotenuse of this small triangle).
- A rectangular notch on the left edge (a leg of this small triangle).
Step 2: Understand the fold mapping.
- The first fold was along the diagonal of the original square.
- The second fold was along the altitude to the hypotenuse, creating the small triangle in Figure IV.
- The hypotenuse of the small triangle in Figure IV corresponds to the outer perimeter of the original square.
- The legs of the small triangle correspond to the diagonal fold lines of the original square.
Step 3: Unfold and reflect.
- The rectangular hole is offset from the center (the right-angle vertex). Since the paper has 4 layers here, unfolding will replicate this hole 4 times, symmetrically placed in the four quadrants. The hole's sides are parallel to the hypotenuse (original square's sides), so the unfolded holes will be upright squares/rectangles, not rotated diamonds.
- The triangular notch on the hypotenuse (perimeter) will be replicated on all four sides of the original square. Since the cut removes material from the edge, the unfolded representation must show a notch pointing inward (missing material from the boundary).
Step 4: Evaluate the options.
- Option A shows notches pointing outward (outside the boundary), which is an incorrect representation of a removed edge piece.
- Option B shows diamond-shaped holes, which implies the cut was rotated 45 degrees relative to the sides. This is incorrect.
- Option C correctly shows upright square holes and inward-pointing triangular notches on all four edges, matching the reflection of the perimeter cut.
- Option D shows a single central hole, which would only occur if the cut was made exactly at the right-angle vertex (the center of the original square).
Answer: C