Here's why:

* Ribosomes are the protein synthesis factories of the cell. They read the genetic code from messenger RNA (mRNA) and use that information to assemble amino acids into proteins.

* Ribosomes are composed of ribosomal RNA (rRNA) and proteins. rRNA makes up a significant portion of the ribosome's structure and plays a crucial role in the translation process.

While other organelles may have some RNA, ribosomes are the primary site of RNA activity and contain the highest concentration of RNA within a cell.