The correct option is A imbibition
Imbibition is the absorption of water or any other solvent (like ether by rubber) by solid particles without forming a solution. Example: Swelling of the seeds when placed in water, absorption of water by dry woods, swelling of gums, etc.
Diffusion is the movement of molecules (solid, liquid, gas) from a region of higher concentration to a region of lower concentration till a level of equilibrium is reached.
The osmotic entry of water into a cell or a system when placed in pure water or hypotonic solution is called endosmosis (hypotonic solution is a solution having osmotic concentration lower than that of another solution).
Turgidity is a condition of a cell being fully distended due to endosmosis.