Homeostasis is the process or mechanism of trying to maintain equilibrium while interaction with the outside world. An example of maintaining homeostasis in the system level would be the endocytosis and exocytosis of a substance.
Endocytosis and exocytosis are the mechanisms in which molecules are brought into the cell and out of the cell depending on their need to the cell.
Starch is a example of a "lipid" or option A. Starch are also a example of a natural polymers and natural polymers are organic substances that are insoluble in water but soluble in other organic mixtures and a example of a natural polymer is starch.