merge or branch?

[Christine & Freight]

Hey Folks~

I am having a dispute with a co-worker over how to do something in CVS.  I
was wondering if anyone out there can help?  Here's the situation:

A branch (let's call it branchA) gets created off the main line.  Then, at
some point in time, a branch (branchB) gets created off of branchA.

Development continues down branchA, and a new directory, with new files,
gets added and committed on branchA.  This new directory is obviously not on
branchB, since it was created after branchA was created.

Question: how does one get the new directory from branchA onto branchB?

We have two answers:

1. merge the directory from branchA to branchB.  I had a little trouble
coming up with the command to do this (I am new to CVS), but that was the
obvious answer to me. (in a branchA sandbox, do a cvs update -j branchB
filename, or dirname????)

2. branch the new files in the new directory using the branchB branch tag.
In other words: cvs tag -b branchB newfilename.

My thoughts are option #2 will create another branch, with the same name
(branchB) in cvs.  I believe that option 2 will give my colleague what he
wants, but I still believe two separate branches were created and merging
would have been the better way to go as it would have brought the files over
to the original branchB branch.

Any opinions?

Thanks so much!
~Christine