Final answer:
Water will move along its osmotic pressure gradient during osmosis. This action helps achieve balance between solute concentrations inside and outside a cell's membrane.
Step-by-step explanation:
If there is a difference in osmolarity between a cell and its environment, water will move along its osmotic pressure gradient, which is the correct choice (b). This movement of water is referred to as osmosis, a fundamental concept in biology, which is the diffusion of water across a selectively permeable membrane.
Osmosis is essential for maintaining the proper balance of fluids in the body and across cell membranes. The body constantly adjusts water movement into and out of cells to maintain a stable internal environment. The direction of osmotic flow depends on the relative concentrations of solutes inside and outside the cells, and it is driven by the goal of reaching an isotonic state, where the solute concentrations are equal on both sides of the membrane.