This example shows how to build interactive dropdown menus with React. It defines a reusable `Dropdown` component that renders an HTML `<select>` element and maps an array of pet options into `<option>` tags. The app tracks the currently selected value with React state and uses `ReactDOM.render` to display the interface. The code also imports the `Dropdown` from a separate file and uses the `useState` hook to manage and log selection changes.