This choropleth map displays Canadian provinces colored by an arbitrary cost index, with gray indicating missing data. Built with D3 v7, it loads a Canada GeoJSON file and joins it to the linked dataset on province name. The map uses a Mercator projection via `d3.geoMercator` and renders paths with `d3.geoPath`. A sequential color scale maps the cost index values, and interactive tooltips appear on mouseover, while a linear gradient legend explains the color encoding.