Solutions A and B are separated by a semi-permeable membrane and water moves from A to B. Hence, solution B is
Hypertonic
Isotonic Solution: The relative concentration of water molecules and the solute on either side of the cell membrane is the same. Hence there is no net movement of water molecules.
Hypertonic solution: In this condition, the solution outside the cell has a higher solute concentration than the fluids inside the cell. Therefore exosmosis takes place i.e. water moves out from the cell.
Hypotonic solution: In this condition, the solution outside the cell has a lower solute concentration than the fluids inside the cell. Thus, endosmosis takes place i.e. water enters the cell and thus the cell becomes turgid.
Water always moves from a hypotonic to a hypertonic solution.