This visualization shows the number of units or items purchased by each of the top ten sales representatives from a CSV dataset loaded via `d3.csv`. It renders a horizontal bar chart using SVG where bar lengths encode the numeric "Units" values and the vertical axis lists the "Rep" names. Built with React and D3 v5, the app uses `d3.scaleBand` for the categorical y-axis, `d3.scaleLinear` for the quantitative x-axis, and `d3.max` to determine the scale domain, while React manages the state and re-renders the SVG marks.