Final answer:
When the 'Exclusive' option is checked in preferences, only one track can play at a time.
Step-by-step explanation:
When you have the 'Exclusive' option checked in preferences, it means that only one track can play at a time. So, if you have multiple tracks selected and 'Exclusive' checked, only one of those tracks will play at any given time. This can be useful if you want to listen to each track individually without them overlapping or if you want to focus on one track while muting the others.