Answer: (2) endocytosis
Endocytosis is a widespread cellular function that regulates the quantal uptake of exogenous molecules from the cell’s environment via plasma membrane-derived vesicles and vacuoles. Endocytosis occurs in all animal-cell types and can result in the uptake of an enormous spectrum of materials. It also plays an essential role in the physiology of cells and the whole organism. For instance, endocytosis is involved in the transport of food inside the amoeba.