This scatter plot visualizes the relationship between the number of calls handled per month and the average response time for fictional ambulance units. The data points are colored by unit type—Basic, Advanced, or Critical—using a D3 ordinal scale, with a hover tooltip displaying the unit name, call count, and response time. Built with D3 v7, the visualization renders as an SVG and includes labeled axes for calls (x-axis) and response time (y-axis), along with a legend created via `d3.scaleOrdinal` and `d3.axisBottom`/`d3.axisLeft`.