Which of the following processes incurred a liability that had not been recognized as part of an asset retirement obligation?

1-AG Waste buries and backfills a landfill site and periodically monitors the land for settlement and drainage issues.

2-JB Mining goes through a reclamation process that includes reforestation of the area after closing a strip mine.

3-VB Mills tears down its factory and turns the property into a park after the building is destroyed by a tornado.

4-TR Drilling dismantles and removes an offshore oil platform at the end of its useful life.