Final answer:
COPI-coated vesicles are responsible for transporting materials from the Golgi complex back to the ER. COPII-coated vesicles are associated with transport from the ER to the Golgi, while clathrin-coated vesicles handle transport to various other cellular destinations.
Step-by-step explanation:
The COPI-coated vesicles are responsible for moving materials from the Golgi complex toward the endoplasmic reticulum (ER).
In the cellular process of protein sorting and traffic, COPII-coated vesicles bud from the ER and transport their contents to the cis face of the Golgi apparatus. After the proteins and lipids are processed and modified within the Golgi apparatus compartments, they may need to be sent back to the ER for various reasons, such as retrieval of ER-resident proteins. This retrograde transport from the Golgi to the ER is facilitated by COPI-coated vesicles. In contrast, clathrin-coated vesicles are primarily involved in transporting materials from the trans Golgi network to endosomes, lysosomes, and the plasma membrane.
The cadmium-coated vesicles mentioned in the question are not a recognized part of cellular transport processes, indicating that option 4 is not a correct answer. Regarding the provided options, COPI-coated vesicles (option 2) are the correct answer to the question.