What happens if plants encountered multi-directional stimulus?

What information is used by plants to determine if they are growing in the shade or the open canopy? How does a“sun plant” respond once it detects that it is growing in the shade? How Is this different from the response you would expect from a“shade plant”?

What is the primary function of guard cells?   Question 28 options:   They store carbohydrates.   They help support the plant.   They absorb minerals from the soil.   They control the size of the stomata.