C) allows users, not developers. Why? Because the FileMaker environment is not able to determine permissions of volumes.
B) the same as Windows. The dialogue box shows or hides the "New Folder" button depending on the script step option
A) not exactly, it's only a button on the dialogue box. On Mac, you can Control Click on the directory window and it allows creation of a folder.
It's all GUI - but the good part is, the result is returned into the variable, so it's a great feature.
PS: g'day from Sydney
PPS: If you want some pretty advanced folder and file handling functions, I would be checking out the base elements plugins. They ROCK!