The options you get are determined by the program (or app) you're running to do it. There are programs that you can download free that will do it. But the B2 will also do it for you. When you first plug it in, the B2 will act as if nothing is there. Run the "Format USB C" (or A) command and it will format the disk as FAT32. The larger the disk is, the longer the process takes, but it's not long (but should not be instantaneous).
Warnings:
- Everything on the disk to be formatted will be lost, so copy it off first.
- Do not run the "Format HDD" command by mistake, as that will erase all the music stored on the B2. (We've known it to happen.)