Which of the following statements is correct about Osmotic Pressure?

• A.It is the pressure required to prevent a solute flowing across a semi-permeable membrane from high to low region of concentration
• B.It is the pressure required to allow a solvent flowing across a semi-permeable membrane from high to low region of concentration
• C.It is the pressure required to prevent a solvent flowing across a semi-permeable membrane from a region of high to low concentration
• D.It is the pressure required to prevent a solvent flowing across a semi-permeable membrane from a region or low to high to concentration