This line chart visualizes restaurant expenses over time, plotting yearly profit data as a smooth blue curve. The visualization uses D3 v5 with an SVG renderer, employing `scaleLinear` for both axes and `line` with `curveBasis` for the curved path. Axis labels and a title are added, while the data comes from a CSV file about San Francisco restaurants, loaded via `d3.csv`. Gridlines are generated through tick marks with negative lengths.