I have looked through other questions on similar question.
But they seem to say the answer is  git fetch --all.
But in my case, it doesn't work.
This is what I have done for it.
> git branch
* master
> git branch -r
origin/master
origin/A
> git fetch --all
> git branch 
* master        #still not updated
> git fetch origin/A
fatal: 'origin/A' does not appear to be a git repository
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
> git fetch remotes/origin/A
fatal: 'origin/A' does not appear to be a git repository
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
And I also tried git pull --all also but the result is the same.
-------------------Edit-------------------
> git pull --all
Already up-to-date.
> git branch 
* master              # I think it should show branch A also
> git remote show origin
 HEAD branch: master
 Remote branches:
   A      tracked
   master tracked
-------------------Edit-------------------
> git pull origin A
 * branch            A       -> FETCH_HEAD
Already up-to-date.
> git branch 
* master                   # I think it should show barnch A also
 
     
     
    