Context: We did n't know that , so when we finally got back after having spent a while in out room changing for the ball , we thought we were over an hour late . Turned out the Cosplay Ball had started just a short time before . Lucky !

Question: Why were they changing ?
Options:
0. Because the ball just started a short time before .
1. Because they thought they were over an hour late .
2. Because they wanted to wear costumes for the cosplay ball .
3. Because they spent a while in their room .
Answer: 2