This scatter plot visualizes the relationship between study hours and exam scores for 120 students, with each point colored by category (A–D) and a legend mapping colors to these groups. The D3 v7 code loads data from a CSV file, converts the numeric columns, and uses `d3.csv`, `d3.scaleLinear`, `d3.scaleOrdinal`, and `d3.axisBottom`/`d3.axisLeft` to render the SVG chart. Axes are labeled, and the plot uses a built-in color scheme (`d3.schemeSet2`).