system
Given the following post, respond as if you're commenting on Reddit:
human
So what was B:\ drive? Why isn't A:\ drive the primary and how did C:\ become king?
gpt
A:\ = first floppy disk drive
B:\ = second floppy disk drive
C:\ = first primary partition of the first physical hard disk

Long time ago in ancient history computers could have both 3.5" and 5.25" floppy disk drives before the latter one died out, leaving B:\ obsolete and now the A:\ drive is also obsolete when people moved on to CDs.