Test Yourself: Prerequisites

Which parts of the document get rerendered after the timer updates in the code below?

function tick() {
  const element = (
     <div>
      <h1>Hello, world!</h1>
      <h2>Time = {new Date().toLocaleTimeString()}.</h2>
     </div>
  );
  ReactDOM.render(element, document.getElementById('root'));
}

setInterval(tick, 1000);