in my version control I have:
- master
 - branchA
 - branchB
 
branchA was checked out from master and branchB was checked out from branchA:
master -> branchA -> branchB
Questions:
- if I update and push to branchA then how do I pull the update into branchB?
 - is there a way to verify what is the origin of a particular branch (I mean where it was checkout out from, sorry if the terminology is incorrect)