Diffusion of water through selectively permeable membrane is

The correct option is osmosis.

To understand why this is the correct answer, let us break down the key terms and concepts:
1. Diffusion: This is the general passive movement of particles (atoms, ions, or molecules) from a region of higher concentration to a region of lower concentration, down their concentration gradient, until they are evenly distributed.
2. Osmosis: This is a specific type of diffusion. It refers specifically to the net movement of water molecules (solvent) from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution) through a selectively permeable membrane (or semi-permeable membrane).
3. Selectively Permeable Membrane: A membrane that allows certain molecules or ions to pass through it by active or passive transport, while blocking others. In biological systems, water molecules pass freely across this membrane, while larger solute molecules cannot.
4. Imbibition: This is a special type of diffusion where water is absorbed by solids (colloids) causing them to enormously increase in volume (e.g., seeds swelling up when soaked in water). It does not necessarily involve a selectively permeable membrane.
5. Translocation: This refers to the movement of materials (like nutrients and sucrose) from leaves to other tissues throughout the plant, typically through vascular tissues like phloem.

Therefore, when we specifically describe the movement of water molecules diffusing through a selectively permeable membrane, the biological term for this process is osmosis.