AllSync & AllDup

When I do a search, does Allup return all files groups within my search parameters that contain duplicates - plus the originals?

So when I go to delete the duplicates, I should retain at least one file in each group as one is likely to be the original?

In "File Manager", should I tick "Do not ...

My first search was for duplicates of all photo's & images in my C Drive. I found many duplicates within the over 3000 files located but never less than 2 "duplicates" Can I safely delete all of the duplicates found knowing that there will still be one *original* (still in the C Drive?) of every ...