Option B: The two-building solution.
Option A complicates the infterface, and with 2 "seperate but still the same" level-ups it will be even more confusing to players.
Option B merely adds another "bank" for the research points (nearby the Bank that holds the money). And it enables the upgrading of both at the same time.
I don't really see the appeal of the "seperate lab speed/max" and I'm amazed it was the #1 suggestion for RN addon, but let's go with it...