That would be the Endoplasmic Reticulum my good friend hope this helped... :D
Guard cells use osmotic pressure to open and close stomata, allowing plants to regulate the amount of water and solutes within them. In order for plants to produce energy and maintain cellular function, their cells undergo the highly intricate process of photosynthesis
It is apart of cellular DNA an ATP, and is a major component of bones and teeth, it is often only available in limited quantities in the the environment.
ANSWER IS C HOPE IT HELPS :D