Choose the box that is similar to the box formed from given sheet of paper (X).

Concept: When a flat net of six squares is folded into a cube, two squares that share an edge in the net become adjacent (touching) faces of the cube. If a third square continues in the same straight line beyond a shared neighbour, it folds around to become the face directly OPPOSITE the original square — not opposite the shared neighbour, which instead ends up adjacent to both. So a folded cube can only be genuine if every pair of markings shown touching in the picture is a pair that is actually adjacent in the net — never a pair the net forces onto opposite faces.

Application:

1. In sheet (X), the plain (blank) square at the centre of the cross has three net-neighbours: the dotted square above it, the ⊕ square to its left, and the shaded square below it.

2. Two steps above the centre square, in the same straight line as the dotted square, sits a second blank square. When the net folds up, that second blank square swings around to lie directly opposite the centre square.

3. That leaves the ⊕ square and the one remaining blank square (the one attached beside the dotted square) as the last unmatched pair, so they must be opposite each other.

4. The three forced opposite pairs are therefore: dot ↔ shaded, ⊕ ↔ blank, and blank(centre) ↔ blank(top).

5. Checking every figure against these pairs: figure (2) shows the dotted face and the shaded face sharing an edge — forbidden, since they must be opposite. Figure (4) also shows the dotted face and the shaded face sharing an edge — forbidden for the same reason. Figure (3) shows all three blank faces meeting at one corner, but one blank pair is a forced-opposite pair, so they can never appear together in a single view — forbidden. Figure (1) shows the dotted face next to the ⊕ face only, which is not one of the forbidden pairs — allowed.

Cross-check: fold the net mentally by holding the centre square as the front face, the dotted square as the top face, and the ⊕ square as the left face. The top and left faces of any cube always share an edge, exactly as figure (1) shows — confirming the result independently of the elimination above.

Only figure (1) can be formed from sheet (X), so the correct choice is “1 only”.