A change in the orientation of the microfibrils in the cell walls of the guard cells
The loss of water in the guard cells
A change in the turgidity of the guard cells
None of the above
Solution
The immediate cause of the opening or closing of stomata is a change in the turgidity of the guard cells. The increase in turgidity within the guard cells leads to the opening of the stomata, and the loss of turgor causes the stomata to close.