Having some issues with .DSK files....on my //GS

["Marvin Miller" <marvinmiller@hotmail.com>]

Hi;

I have a whole bunch of .dsk files on my apple//gs. I am using Asimov to
make 5.25 floppy's. When you do it you get the option of Dos 3.3 or ProDos.
I've been wondering;

I have the DOS 3.3 FST installed, how come I can't format the 5.25's as DOS
3.3?
Can you use Dos 3.3 on the apple//gs?
How can you tell whether the .DSK file would be 3.3 or ProDos?

Thanks;
Marvin Miller