In darkness, stomata close due to:
Answer: B) Exosmosis of water. For STOMATA MOVEMENT, remember the key idea and you’ll land on this option; the distractors usually swap cause and effect or confuse similar terms. Avoid: A) Increase in turgor pressure; C) K⁺ accumulation; D) Decrease in CO₂. Name the process first, then pick the option that describes it — don’t reverse cause and effect.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.