Which process are the guard cells associated with?

Which one is not related to transpiration?

When do the stomata open?

In darkness,the stomata close because:

$A-$ The inner wall of each guard cell,towards the pore or stomatal aperture,is thick and elastic.
$R -$ Cellulose microfibrils are oriented longitudinally in the cell walls of the guard cells.

Which of the following statements is not true for stomatal apparatus?