Question: Starting with some DOM elements in the nested structure below, you assign listeners for the same event to a child element and one of the parents using the JavaScript that follows. You want to ensure that when `.leaf` is clicked, only its event handler will be fired, instead of the click bubbling up and also firing the parent's click handler. What do you need to add to its handler function?

1. `event.capture();`
2. `event.stopPropagation();`
3. `event.preventDefault();`
4. `event.stop();`

Answer: The correct answer of the above question is Option B:`event.stopPropagation();`