Final answer:
Without specific solute names, we postulate the greatest concentration change would involve a small, nonpolar or small polar solute capable of moving through the phospholipid bilayer by simple diffusion or osmosis, likely resembling water.
Step-by-step explanation:
The question revolves around the distribution of various solutes across a synthetic phospholipid bilayer, seeking to understand which solute exhibited the greatest concentration change. Given the nature of phospholipid bilayers, large polar or ionic molecules cannot easily diffuse through due to their hydrophilic nature and size. Charged particles, regardless of size, are repelled by the hydrophobic core of the bilayer. However, small polar molecules like water can move through via simple diffusion. Since solutes are not specified individually by name in the given options (A, B, C, D), we cannot make a distinction without additional information. That being said, we know osmosis is critical - it is the movement of water across a membrane from a lower solute concentration to a higher one. Water molecules facilitate the process of equalizing solute concentrations on both sides of the membrane, which is a passive transport that doesn't require energy. Therefore, the greatest change in the distribution of concentration would be noted with the 'solvent' that most readily moves across the membrane, which in this case would likely be a small, nonpolar or small polar substance such as water.