Backing up folders & files

[DannyG]

I'm looking to SuperDuper for backing up select folders and files. Here is my set up and what I would like to do.
HD1 - hard drive on computer
HD2 - external hard drive
HD3 - external hard drive

Backup -
Folder-A on HD2 backs up to HD3
Folder-B, and files 1,2,3 on HD1 back up to HD3

Schedule -
Automatically on a daily basis.

Questions-
1. Will SD recognize file changes within sub-folders of Folder-A and just backup those changes, or, because I'm backing up "Folder-A" does SD see the file change as a change to Folder-A and backup the entire folder again. (Folder-A exceeds 120 GB and I don't want to be backing up the entire folder each time, just the added or changed files.)

2. I have Folder-A with it's sub-folders and files on HD2 backing up to HD3. I also have a different folder on HD3, let's call it Folder-C, that has some of the same files found in Folder-A. When doing the backup, will SD ignore Folder-C or will it see the files in Folder-C and not include those in the backup of Folder-A?

Thanks in advance for any help.
Dan