Osmosis drives water into the tube, diluting the solution

Steps:

• Water moves from high water potential (outside) to low (inside tube X via semi-permeable membrane).
• Inflow of water raises liquid height in tube X.
• Added water dilutes salt ions, lowering concentration.
• Process continues until equilibrium.

Why C is correct:

• Osmosis follows the law that solvent diffuses across a semi-permeable membrane from dilute to concentrated side until concentrations equalize.

Why the others are wrong:

• A: Wrong; height increases due to water influx, not decreases.
• B: Wrong; concentration decreases from dilution, not increases.
• D: Wrong; both height and concentration change oppositely to osmosis direction.

Final answer: C