This stacked bar chart shows how student grades are distributed across five subjects, with each bar representing a student and colored segments showing the percentage of their total score in each subject. The visualization uses d3.stack() to create stacked series and d3.scaleOrdinal for color mapping, while d3.axisBottom formats tick labels as percentages. A tooltip appears on mouseover, displaying the exact percentage for each subject segment using d3.format. The data comes from a CSV file where scores are normalized to sum to 1 for each student.