This reproduction of a Sol Lewitt conceptual piece uses D3 to generate a grid of horizontal and vertical line segments across the full viewport. The lines are masked so that only a circular area at the center is visible, with the horizontal lines appearing inside the circle and vertical lines outside it. The code builds SVG rectanglesselectable via D3’s `select` and data joins, and defines two mask elements using `append('mask')` with nested rect and circle shapes. The result is a geometric composition derived entirely from procedural SVG rendering.