The correct answer is true.
It is true that according to 2 Peter, the Lord will return like a thief, unexpectedly, and will catch the unbelieving world unprepared even as He did when he swept Pharaoh’s army away.
This Biblical metaphor is important because it conveys the message that Catholic followers have to be ready at any time if the Lord calls them. Nobody knows for sure the time and the place of the Lord. So it is better to have no sins and do good actions to be ready for that call of the Lord. So in a few words, it is better to be prepared and be good people, instead of fearing judgment day.