Final answer:
A) Osmosis. The reason the solution level rose on one side while it decreased on the other is due to osmosis, which is the passive movement of water through a semipermeable membrane to balance solute concentrations.
Step-by-step explanation:
In the scenario where the solution level on the left side rises while the solution level on the right side decreases, the correct answer is A) Osmosis. Osmosis is the diffusion of water across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration.
This movement of water happens passively and aims to equalize solute concentrations on both sides of the membrane. The water will move towards the hypertonic solution, where the concentration of solute is higher, causing the solution level to rise on one side and decrease on the corresponding side, as water leaves that area.
In this case, osmosis is responsible for the change in solution levels due to the passive movement of water molecules through a semipermeable membrane to balance solute concentrations.