The element plays an important role in opening and closing of stomata is

Correct option is B

The correct answer is: B) Potassium Potassium ions regulate the osmotic pressure in guard cells, causing them to swell or shrink, thus opening or closing the stomata. This is essential for gas exchange and transpiration in plants.
Information Booster: • When potassium enters guard cells, water follows by osmosis, opening the stomata. • Its removal leads to water loss and stomatal closure.