AI solution for React Quiz on BFE.dev
1. React re-render 1

The code outputs the following by console.log:

App
A
B
C
D

Explanation:

• When ReactDOM.createRoot is called with <App/>, the App component is mounted and the useEffect hook is triggered, resulting in a state update.
• The App component returns two elements: <A state={state}/> and <D/>.
• When <A/> is rendered, the component A is mounted and calls a child component <B/>.
• When <B/> is rendered, the component B is mounted and calls <C/>.
• <C/> is mounted and returns null.
• Finally, <D/> is rendered and component D is mounted.

Note that the order of the console logs may vary based on the timing of the rendering and mounting of each component. However, the App log will always come first as it is the top-level component.