The independent clause in the sentence is "we returned it." This is the answer because if you say the sentence alone it makes since and it does not need another sentence to support it. Furthermore, the dependent clause in that sentence is "Because the shirt had a tear,". This does not express a reasoning for the shirt having a tear. But, "we returned it", has a subject and a verb. "we" is the subject, and the action of returning is the verb. I hope this has been helpful. : )
Why do you need help with this question? It’s just asking you to give an example of an experience in your life that made you question your life and your approach to it.