Which RNA type is immediately translated after transcription in prokaryotes?

In prokaryotes, the type of RNA that is immediately translated after transcription is mRNA. During prokaryotic gene expression, transcription occurs in the same cellular compartment and often simultaneously with translation. As soon as the mRNA strand is synthesized by RNA polymerase, ribosomes attach to the growing mRNA molecule and begin the translation process to synthesize proteins. This direct coupling of transcription and translation is a defining characteristic of prokaryotic cells.

In contrast, pre-mRNA refers to the precursor mRNA that undergoes processing in eukaryotes before it is translated, which is not applicable to prokaryotes. rRNA and snRNA serve different functions; rRNA is a structural and functional component of the ribosome, while snRNA is involved in RNA splicing, which also does not occur in prokaryotes. Thus, the function and direct translation of mRNA in prokaryotes makes it the correct choice.