Video not exporting with sound

i have a school project, i have have edited the video in blender 2.79. but when i render the video, the sound is not appearing, i am very sure i have all the settings right, please look over, and if it renders with sound for you, PLEASE send me video file as soon as possible (i am currently pretty stressed)! here is the blender file:
work out vid.blend (449.9 KB)

i have looked at tutorial videos, done same settings, and still not work. this is literally my last hope, so please figure this out.