You answered C...

Nothing at the time but later that day find Jo and say: Jo, I know you’ve had enough of Hugh. However, I was alarmed to see you having it out with him in front of the whole room because being criticised in public probably made things much worse for Hugh - it might also make people worry about whether you would do the same to them if they crossed you. I am keen for you to apologise to Hugh, in some way.

This is our favoured answer too. It shows that you have noticed Jo’s exasperation but that you have also chosen to give her feedback about how she communicated with Hugh. Your suggestion of an apology might also repair a little of the damage Jo inflicted by reprimanding him in public.