Final answer:
The Golgi apparatus is the part of the endomembrane system mentioned in the provided options. This system is integral for handling proteins and lipids in the cell, though structures like ribosomes and mitochondria are not included.
Step-by-step explanation:
The part of the endomembrane system that is listed among the options provided by the student is the Golgi apparatus. This system is crucial for numerous cellular processes, including the modification, packaging, tagging, and transportation of proteins and lipids that contribute to the cell's membrane structure. The Golgi apparatus works in conjunction with other components such as the nuclear envelope, endoplasmic reticulum (ER), lysosomes, vesicles, and the plasma membrane. It is important to note that the endomembrane system does not include structures like ribosomes, the cytoskeleton, flagella, or mitochondria.