Abscisic acid is an antitranspirant. It prevents transpiration by

• A. Forming a film impervious to water over the stomata
• B. Preventing K+ ion uptake, thus decreasing the osmotic concentration of the guard cells and keeping them flaccid
• C. Inducing starch formation, thus decreasing the osmotic concentration of the guard cells and keeping them flaccid
• D. Increasing respiration, thus increasing\[C{{O}_{2}}\]concentration in the guard cells which helps in keeping the guard cells flaccid