Southampton:

The city has undergone many changes to its governance over the centuries and once again became administratively independent from Hampshire County as it was made into a unitary authority in a local government reorganisation on 1 April 1997, a result of the 1992 Local Government Act. The district remains part of the Hampshire ceremonial county.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What act was responsible for the reorganization of local government on April 1, 1997?
1992 Local Government Act