Answer:a
Explanation: because naturally it occurs anytime it wants to
Stomata are tiny pores present in the leaf that allows gas exchange and is where water vapour leaves plants and carbon dioxide enters. Special cells called guard cells present in the stomata, control each pore's opening or closing. When stomata are open, transpiration rates increase; when they are closed, transpiration rates decrease.
A) Sodium..................................................
The blade is the flattened portion of the leaf. These expanded blades are called lamina which are attached to the plant stem by the petiole. They come in diverse shapes, sizes, and other characteristics. The other choices are just supporting structures of this structure of the plant.
Well, an endoskeleton is an internal skeleton, like humans have.
Pro: Bones do not get broke as easily, since they are inside of the body. Bones that break also heal more quickly in an endoskeleton, since they have tissue and blood surrounding it and transferring nutrients.
Con: The flesh can get easily damaged. There is no shedding with endoskeletons, so a new skeleton cannot be grown in the event of an injury.