A video has two <track> elements: a subtitles track marked default and a captions track. Both have the same srclang. Which track does the browser auto-enable on load?

<video controls> <source src="clip.mp4" type="video/mp4"> <track kind="subtitles" src="en.vtt" srclang="en" label="English" default> <track kind="captions" src="en-cc.vtt" srclang="en" label="English CC"> </video>