Origin Of The Option Key Symbol

Couldn't find a general area to post this question. And I've used Google and Ask (and even Wikipedia, yes!) to search high and low for an answer, and have come up empty handed.

Does anyone know what the Option Key symbol actually represents? The history of how it ever came to be? I wonder what the symbol is.... well.... symbolizing?

I thought it looked a bit like an escalator seen from the side (So your option is to take the escalator or stairs?). An Apple Store employee said you can imagine it as a path on a road, and at the top of the symbol is a "fork in the road" - thus choosing your direction, left or right.

But does anyone actually know? For those of you not even sure which symbol I am referring to, it is this:

⌥

Thanks!