What happens to the guard cells when water flows into them?

Correct option is B

The correct answer is (b) Stomatal pores open.
 When water flows into the guard cells, they become turgid, meaning they swell up due to the water pressure.
 This turgidity causes the guard cells to change shape, creating an opening between them, which results in the opening of the stomatal pore.
 The opening of stomatal pores allows gas exchange; carbon dioxide enters the leaf for photosynthesis, and oxygen and water vapor exit the leaf.
 The regulation of stomatal opening and closing is crucial for maintaining water balance and facilitating gas exchange in plants.
Information Booster:
Guard Cells and Stomatal Function:
 Guard cells are specialized cells located on the leaf epidermis that surround each stomatal pore.
 The influx and efflux of water in guard cells are regulated by osmotic pressure, driven by the accumulation or loss of solutes such as potassium ions.
 When guard cells lose water and become flaccid, the stomatal pores close to prevent water loss.