C. modifying, sorting, and packaging proteins prior to transport.
Explanation:
The Golgi apparatus is the cell organelle present in eukaryotes only. It consists of stacks of flattened membranous sacs which are called as cisternae. The newly formed proteins are carried from ER to the Golgi apparatus which process, sort, and modify them. These modified proteins are then sorted to their respective destination. In this way, it serves to maintain the constant internal environment, that is, homeostasis.
