Yes, A and C, not A and B.ok. tube f is a tube full of water which connects a water medium to another water medium.
Have you lost track of where we are at?
You need to make a list of the pairs of surfaces which are connected by a water only path, and a list of pairs connected by an air only path.
In post #56 you claimed there was such a path connecting A and B. Are you ready to agree there is not one?