You probably decide to open 2NT.
(As an aside: In my view the hand is rock bottom minimum for this action. If partner Passes
this and puts down rubbish it is the sort of hand where you will probably struggle to make five
tricks. Those pairs who play a 2NT opening bid as 19-20 points must be used to recording
-300 on a regular basis).
Anyway, partner raises to 3NT, everybody Passes and the
Q is plonked on the table by the
left hand opponent. This is your problem now as South: