This pie chart visualizes monthly expenditures by department, using color-coded slices with department labels positioned at each arc’s centroid. A legend to the right maps each color to its department and expenditure value. The code loads CSV data via `d3.csv` (D3 v5), then uses `d3.pie` and `d3.arc` to generate the SVG paths, with `d3.scaleOrdinal` assigning colors. The visualization is rendered as an SVG with a fixed 960×500 canvas.