multidb with multi version on my site ?

Hey guy i just import multidb plugin to my plugin folder, but on my admin panel i saw there is few version there, which one to activate ? or i done some mistake ? this is scary experience.
thanks

Multi-DB
Network Activate | Delete

Version 2.9.2 | By Andrew Billits (Incsub) | Visit plugin site
Select Multi-DB Multi-DB
Network Activate | Delete

Version 3.0.5 | By Andrew Billits
Select Multi-DB Multi-DB
Network Activate | Delete

Version 2.9.2 | By Andrew Billits (Incsub) | Visit plugin site
Select Multi-DB Multi-DB
Network Activate | Delete

Version 2.9.2 | By Andrew Billits (Incsub) | Visit plugin site
Select Multi-DB (Conversion Tool) Multi-DB (Conversion Tool)
Network Activate | Delete

Version 2.9.2 | By Ron Dillehay - FanMail to rdillehay@hotmail.com (no tech support please) - Modified slightly by Andrew Billits (Incsub) | Visit plugin site