This bar chart visualizes the average number of social media platforms used by individuals, grouped by their self-reported anxiety level. The data, sourced from a CSV file on student grades and mental health, is filtered to remove missing or invalid entries. Using D3 v7, the code computes the mean number of platforms for each anxiety category with `d3.group` and `d3.mean`, then renders the results as an SVG bar chart. Bars are sorted in descending order and change color on hover, with axes and labels provided by `d3.axisBottom` and `d3.axisLeft`.