Replay audio when user returns to a slide

I have a slide with multiple layers and two audio tracks (Intro and Select Options) on the time line. The layers are "Arrival", the next is "History", and the last is "Documentation". 

When the user comes to the slide the first time they will hear both tracks. Then the user will choose 1 of the 3 options to review and then come back the base layer to view the next one. I was able to set up the variables so that the first track, Intro, is only played once. But I want the second track, Select options, to replay when the user returns to the base layer as a prompt to select the next option. 

What is the best way to set up the variables and triggers?