The correct option is D Osmosis
Osmosis is the spontaneous net movement of solvent (water) molecules through a semi-permeable membrane into a region of higher solute concentration, in the direction that tends to equalise the solute concentrations on the two sides.
In a hypotonic solution, the total molar concentration of all dissolved solute particles is less than that of another solution.
In a hypertonic solution, the total molar concentration of all dissolved solute particles is more than that of another solution
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.