A React example demonstrates building a dropdown menu using the `useState` hook to manage selected values. The app renders a list of pet options, with the initial selection set to "Rabbit". It uses the `Dropdown` component, a reusable `<select>` element that takes `options`, `id`, `selectedValue`, and `onSelectedValueChange` props. The code relies on React's `ReactDOM` for rendering and the `useState` hook for state management, with the selected value logged to the console.