After cutting cucumber if salt is added, then water comes out due to

The correct answer is C) Osmosis. When salt is sprinkled on a cut cucumber, the salt solution outside has a lower water potential than the cucumber cells. Water moves out of the cells across their semi-permeable membranes, from the region of higher water potential to lower, and this loss of water is what you see as liquid collecting on the surface. This process is called plasmolysis when it occurs in plant cells.

• A) Active transport is wrong. It needs metabolic energy (ATP) and carrier proteins to move substances against a concentration gradient. Salt drawing water out needs no energy input.
• B) Passive transport is a broad umbrella term covering diffusion, osmosis and facilitated diffusion. It is true in a loose sense, but the question asks for the specific mechanism, which is osmosis.
• D) Diffusion is the net movement of particles down a concentration gradient. Here the specific movement is water across a selectively permeable membrane, which is osmosis.

The concept links to the plant water relations chapter of Class XI biology and to Mains questions on food preservation, since salting and sugaring (osmotic preservation) work on this same principle.

Trap: Students pick passive transport because osmosis is passive. The exam wants the most specific correct term, and that is osmosis.