Final answer:
The prokaryotic ribosome is composed of three RNAs (5S, 16S, and 23S rRNA) and many proteins, making up the 70S ribosome with 50S and 30S subunits.
Step-by-step explanation:
The prokaryotic ribosome consists of three RNAs and many proteins. Specifically, the small subunit of a prokaryotic ribosome, which is known as 30S, contains the 16S rRNA. The large subunit, referred to as 50S, contains both the 5S and 23S rRNAs. Together, the small and large subunits comprise the 70S prokaryotic ribosome, which is involved in the synthesis of proteins within the cell. Hence, the correct answer to the question is option (2): "three RNAs and many proteins".