Generally if the amount of a substance is equal on both sides of a semi-permeable membrane, nothing is going to happen unless active transport takes place.
However, in this case, nothing would happen since active transport doesn't seem to be used, as I've mentioned before.
Usually, particles move from areas of high concentration to low concentration (from places where there are a lot of particles to places where there are few particles).
However, here we see that there are equal amounts of H+ ions on both sides of the membrane, which means that there would not be any net flow of ions to either side.
Thus, the answer is A (the H+ ions will not flow).
