Unity 3.5 Android upgrade to 4.0

hi everyone. before i upgrade to Unity3D 4.0, i have Unity Android 3.5, can i still have Unity Android 4.0 after i upgrade ?

If you have a license for Unity Android 3.5, then this license is valid for all the Unity 3.x versions, but for the 4.x version, you will need to purchase another license. Then again, that license will be valid for all the 4.x versions.