Correct Answer - D
If a living plant cell is immersed in water, it swells due to absorption of water (endormosis). As a result of entry of the water into the cell sap a positive pressure is developed in the protoplasm whicn presses against the cell wall. The actual pressure exerted by the protoplasm against the cell wall is the turgor pressure `(TP)`, which is always less than osmotic pressure unless the cell is in distilled water. Due to turgor pressure the protoplasm of a plant cell will press the cell wall to the outside. the cell wall being elastic, pressure the protoplast with an equal and opposite force. the force exerted by the cell wall over the protoplast is called wall pressure `(WP)`. Normally wall pressure is equal and opposite to turgor pressure except when the cell becomes flaccid.
