This prototype visualizes the relationship between age and insurance charges across 1,338 patient records from a CSV dataset, with points colored by smoker status and linear regression lines for each group. The chart includes axes, a title, and a hover tooltip showing detailed data. The visualization is built using D3 v7 within a React application, employing `scaleLinear`, `axisBottom`, and `axisLeft` for scales and axes, along with `line` for the best-fit trend lines.