I am almost positive it was C.
I wanted to jump in because it was pretty obvious to me that the person that asked the question and SB were not on the same page.
The person that asked the question was asking because of all of the speculation on this board (dnmun originated) that CAR-TReg cell therapy might enable the re-dosing of AAVs for gene therapy or gene editing.
That is A LOT to try to unpack in a single question if you haven't been privy to the discussion, which SB had not.
Rather than taking the question as 'will CAR-TReg cell therapy enable the re-dosing of AAVs for gene therapy or gene editing', he took it as 'Can CAR-TReg cell therapies be redosed'.
As you can see, that's a pretty simple mistake to make given the context of a quick question at the ASM that was not properly framed.
So in his answer, he was saying that there is nothing that would prohibit the redosing of CAR-TReg cell therapy, even though what they are shooting for to start is a single treatment that persists. His answer had nothing to do with the viability of AAV re-dosing or the ability of CAR-TRegs to help with that.