This visualization shows stacked bar charts comparing wholesale product expenditures—including Fresh, Milk, Grocery, Frozen, Detergents_Paper, and Delicassen—across three customer regions. Each horizontal bar aggregates spending per region, with segments colored by product category. The chart uses d3.stack() to compute the stacked series, d3.scaleBand for the regional y-axis, and d3.scaleLinear for the spending x-axis. Hovering highlights each segment and displays a tooltip with the category and its value, formatted using d3.format. Data comes from the provided CSV file, rendered as SVG elements.