Answer:
Cells regulate water and ion balance by actively transporting ions but not water.
Explanation:
Cells regulate water and ion balance by transporting the water molecules from a region of of high concentration to a region of low concentration passively. Active transport does not maintain the water and ion balance, so the last statement is incorrect.
Rest of the statements are correct.
In the first statement they are saying that in osmosis water from an area of low solute concentration moves towards an area of high solute concentration which is absolutely right. An area which has a low solute concentration has a high solvent concentration and vice versa. In osmosis, only solvent can move because osmosis occurs by means of a semi permeable membrane which does not let a solute molecule to pass by. So the area where solute is less, solvent is more and this solvent tends to move towards an area which has high solute concentration because a high solute concentration will have low solvent concentration .
Second statement is also correct. water cannot cross cell membrane because water is polar while cell membrane is non polar. Non polar cell membrane does not let water to pass through it because water is polar therefore water requires integral proteins named as aquaporins to cross cell membrane.
Statement third is also correct. The osmotic pressure is a measure of solute concentration of a particular compartment. The less is the solute in a compartment, the more will be the osmotic pressure. That simply means that osmotic pressure of a pure solvent will be highest because it does not have solute at all. In contrast to this, a solution will have comparatively low osmotic pressure because of the presence of solute in it.
