Can not play subtitle file for audio file.

[LiveIsLive]

This is my code, It is work for video file, but can not display subtitle for audio file.

public partial class VideoTest : Window
{
	public VideoTest()
	{
		InitializeComponent();
		this.MediaElement.Open(new System.Uri(@"Test.mp3"));
	}

	private void MediaElement_MediaOpening(object sender, Unosquare.FFME.Common.MediaOpeningEventArgs e)
	{
		e.Options.SubtitlesSource = @"Subtitle.srt";
	}
}