Final answer:
D) indirect measure of its solute concentration. Osmotic pressure is an indirect measure of a solution's solute concentration, proportional to the number of solute particles present and influencing
Step-by-step explanation:
The osmotic pressure of a solution is a colligative property that reflects the tendency of solvent molecules to move across a semipermeable membrane from a region of lower solute concentration to one of higher solute concentration to establish equilibrium. This movement is driven by the presence of solute particles, and it can be measured by the external pressure needed to stop further osmosis.
Osmotic pressure is directly proportional to the total concentration of solute particles in the solution, regardless of their size. Notably, substances like electrolytes that dissociate into ions contribute more particles per mass and thus have a larger impact on osmotic pressure compared to non-dissociating compounds such as glucose.
Therefore, the answer to the student's question is (D) indirect measure of its solute concentration.