Usually when it all comes from the same source (and most of the official variant traits don't come from the same source as the base) I'd expect it to be a "choose one" (such as subrace) or something similar, so I'm wondering of their some intent I'm missing. ...
OD&D is Original D&D - it's the very first version, and was a rules variant of Chainmail. BD&D is Basic D&D, and was a rules update of OD&D What we call 1st Ed/1e now was called simply AD&D at the time. 2nd Ed is AD&D 2nd Edition officially. It even says as such on the...