Which of the following facilitates the opening of stomatal aperture?

Which of the following facilitates the opening of stomatal aperture?

Option 1 : Contraction of outer wall of guard cells.
Option 2 : Radial orientation of cellulose microfibrils in the cell wall of guard cells.
Option 3 : Decrease in turgidity of guard cells.
Option 4 : Longitudinal orientation of cellulose microfibrils in the cell wall of guard cells.