Answer: A. Lysosome
Step-by-step explanation:
Phagocytosis is a process of endocytosis. Basically bringing stuff into the cell. Lysosomes are the organelles that break stuff down in a cell.
The material is entrapped/engulfed by the cell with its plasma membrane and inwardly cleaves to create a vacuole in the cell. Lysosomes seek out and break down this material so that its constituents can be utilized.