A pie chart visualizes the distribution of pet types within an adoption dataset. The chart displays proportional slices for each pet type, using color from the `d3.schemeSet2` scale, with slice labels and a legend positioned to the right. The visualization is built with D3 v7, using `d3.rollups` to count records from a CSV file loaded via `d3.csv`, and `d3.pie` to compute arc data. Slices are rendered as SVG paths with `d3.arc`, and hover interactions trigger a tooltip showing the pet type and count.