Ribosomal RNA (rRNA) is made in a specific region of the nucleus called the nucleolus.

Here's why:

* Nucleolus is the site of ribosome biogenesis: The nucleolus is a dense, spherical structure within the nucleus. It's the primary site where rRNA is transcribed and assembled with ribosomal proteins to form ribosome subunits.

* rRNA genes are located in the nucleolus: The genes that code for rRNA are clustered in specific regions of the DNA, and these regions are localized within the nucleolus.

* Ribosome assembly occurs in the nucleolus: Once rRNA is transcribed, it associates with ribosomal proteins synthesized in the cytoplasm and transported into the nucleolus. The assembly of these components into functional ribosomal subunits takes place in the nucleolus.

So, the nucleolus is the central hub for the production of rRNA and the assembly of ribosomes.