Final answer:
The Golgi body receives proteins from the Rough Endoplasmic Reticulum (RER). Proteins synthesized on the RER's ribosomes travel via transport vesicles to the Golgi apparatus, where they undergo modifications and sorting for intracellular transport or secretion.
Step-by-step explanation:
The Golgi body, or Golgi apparatus, receives proteins from the Rough Endoplasmic Reticulum (RER). Once proteins are synthesized on the ribosomes of the RER, they are encased within transport vesicles. These vesicles then fuse with the receiving face of the Golgi apparatus. Inside the Golgi apparatus, proteins undergo further modifications, such as getting tagged with short chains of sugar molecules. Eventually, they are sorted and packed into vesicles for distribution to their destination within the cell or for secretion outside the cell.
The correct answer to the student's question is A) Endoplasmic reticulum.