This line chart shows the average mental wellbeing score across five age groups, from 18–25 to 56+, based on data loaded from a remote CSV file. The visualization uses d3.csv to parse the dataset, then computes group means with d3.mean. A d3.scalePoint maps age groups along the x-axis, while a d3.scaleLinear encodes wellbeing scores on the y-axis. The chart renders an SVG line and circle markers using d3.line, with axes generated via d3.axisBottom and d3.axisLeft.