ios - Facebook - social framework

Question

In the facebook website, they mentioned that "After iOS 6 launches to the public, the SDK will automatically use the native Facebook Login in iOS6 when available. Just enable Login with Facebook and the SDK will ensure your apps work seamlessly on all iOS versions 4.0 and later."
But without social framework having in older iOS, how will it work?
Which facebook api version do I have to use for making my app run on iOS 4.3 till iOS 6.0.1?

Answer 1

As mentioned in the comment by "mstfbsnli", Facebook is providing a framework that works with iOS 4.3 also effectively.
We shouldn't use social framework.