Usually, the A drive is a floppy drive, C is the primary hard drive. Changing the boot sequence allows you to boot a different OS from a different drive. Nowadays,only a very small OS would fit on a floppy disk (if you can even FIND a floppy disk).
Booting from CDrom is more common, especially when install a new OS. The boot sequence routing will automatically check whichever drive is listed first, and if that's bootable media (floppy disk, external drive, USB drive,...whatever), then the computer will boot from the OS on that media. If no bootable media is found, it checks the next drive/media on the list, etc. Just because the A drive is listed first doesn't necessarily mean the computer will boot from the A drive, but it will LOOK there first.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.