RC was always the name brand store brand soda as far as I could tell. If Coke or Pepsi were too expensive, you could buy the store's "Cola!" brand cola, or there was always RC. I never knew anyone who ever really drank the stuff. Maybe because we never see them again if they do? Ever think of that?
Here we see The Construct, where a little girl has been invited to visit the seamless white void. Ah! Refreshments! RC cola! Did you ever wonder why RC cola is found everywhere, but no one you know drinks it? It looks kind of suspiciously red in this old ad from 1959... at least that's the year they THOUGHT it was.
Obviously, this little girl has already drunk some red pill, if she's sitting in The Construct. Apparently RC is what everybody drinks in the "real world". I don't think I've ever seen a bottle of RC with the cap off. I've never seen any in my friends' fridge.
Obviously I've never had any, because I'm still sitting in my cubicle, here in Chicago. I'll let you in on a little secret. None of the elevator buttons in the actual Chicago say "lift" underneath them. We don't call them "lifts" or "Tasty Wheat". We call them elevators, even when we're not shooting up the place. The machines got it wrong.