Final answer:
The nucleolus is the site where ribosomes, involved in protein synthesis, are made.
Step-by-step explanation:
The correct answer is b) Nucleolus.
The nucleolus, located in the nucleus of eukaryotic cells, is the site of ribosomal synthesis and the first stages of ribosome assembly. Ribosomes are organelles made of protein and ribosomal RNA (rRNA), and they build cellular proteins in the cytoplasm. After being made in the nucleolus, ribosomes are exported to the cytoplasm, where they direct protein synthesis.