Really? I wasn’t sure which one I “should” use so I looked at a cable that I had laying around (probably came with a cable modem or something?) and was able to see the wire colors through the connector and it was A. So that’s what I’ve been using when making patch cables or wiring my house.

I guess my question is what’s your experience with where B is used? Mostly I’m just curious, it probably doesn’t really matter for me since I only do networking work in my house.