Context: I heard some cackling in the background ( I hope they were n't watching it on the monitor ) . I tried to do it as quickly as possible . A couple of times , someone tried to open the door .

Question: What is a likely source of the cackling that was heard by the speaker ?
Options:
0. There is a wild animal inside making this noise
1. Someone is choking , making a cackling sound
2. None of the above choices .
3. Someone is watching them and laughing
Answer: 3