A: No price controls, scalpers buy everything and resell at 1000%. Only people who can pay that much get it until the manufacturer ends up at 10x output, which can take a long time.
B: Price controls, at least some distrubution of everyone gets some, less incentive to hoard, stores still allowed to raise prices a little (just not a predatory amount detached from real costs) when the manufacturer does when ramping up production.
The shelves are empty in either case, the difference being a nonzero amount going to poorer people in B.