This bar chart shows the average grades of students grouped by their self-reported stress levels (Low, Medium, High). The visualization uses d3.csv to load a remote dataset, d3.rollup to aggregate the grade means, and d3.scaleBand with d3.scaleLinear to map stress categories and grade averages to the SVG coordinate system. Bars are rendered as SVG `rect` elements, with axis labels and rotated x-axis tick text for readability. The chart highlights the relationship between mental health and academic performance.