This visualization displays patient records as a hierarchical tree, showing each patient’s ID, gender, age, SAT score, race, admin flag, wait time, and department referral as leaf nodes. Using D3 v7 with an SVG rendering approach, the code builds the tree via `d3.hierarchy`, `d3.tree`, and `d3.linkHorizontal` to draw the connecting paths. Node circles and text labels are appended to groups, with styling handled through CSS. The dataset is a static array of patient objects, transformed into the treemap’s nested structure for display.