git version 1.7.4.4

I am working on a new project from my development team. 

So I have just cloned the project. The project has 5 branches. 

I need to know what branch was the latest changes made to. So I can start working on that branch, as that would have the latest changes.

I have looked at the log. However, but that doesn't tell me that branches those commits where made to.

Many thanks for any suggestions,