What does the following HTML code do?
<audio autoplay> <source src="audio.mp3" type="audio/mp3"> </audio>
Displays nothing due to the lack of the "controls" attribute.
Displays an audio player, but does not automatically play "audio.mp3".
Displays an audio player and automatically starts playing "audio.mp3".
Displays an error due to the use of the "autoplay" attribute.