Concept:
A mirror image along a given axis is obtained by reflecting the figure across that axis.
When a figure is reflected, the relative positions of all parts reverse with respect to the mirror line, while their shapes and sizes remain unchanged.
For a mirror placed along the \(XY\)-axis, the left–right orientation of the figure is reversed.
Explanation:
Observe the positions of the shaded (black) triangular parts in the original figure.
After reflection across the \(XY\)-axis, each shaded region must appear at the symmetric position on the opposite side of the axis.
The internal diagonal lines and the central small square must also appear as mirror images, not rotated or rearranged.
Among the given options, only Option (C) correctly shows:
Proper left–right reversal of the shaded regions,
Correct symmetry of the diagonals,
Exact mirror placement of the central shape.