Transcription can be coupled with translation in bacteria because :

The correct answer is Option (1) → There is no separation of cytosol and nucleus.

Option (1) There is no separation of cytosol and nucleus. — Correct. Bacteria are prokaryotes with no nuclear membrane, so the mRNA is made in the same place where it is read. Translation can therefore start on an mRNA that is still being made.

Option (2) Post-transcriptional processing of RNA is a simple process. — Incorrect. Bacterial mRNA needs no processing at all to become active; capping, tailing and splicing belong to eukaryotes.

Option (3) Transcription is a faster process than translation in bacteria. — Incorrect. NCERT does not link the coupling to the speed of either process; translation can begin on the mRNA while it is still being made because both take place in the same compartment.

Option (4) RNA molecule has a complex structure. — Incorrect. The structure of the RNA has nothing to do with it; a bacterial mRNA is active as soon as it is made.

Note: The original NTA paper prints Option (3) as “Transcription is a faster process than transcription in bacteria”; it has been corrected to “Transcription is a faster process than translation in bacteria”.

NCERT Extract:
Types of RNA and the Process of Transcription – “… In bacteria, since the mRNA does not require any processing to become active, and also since transcription and translation take place in the same compartment (there is no separation of cytosol and nucleus in bacteria), many times the translation can begin much before the mRNA is fully transcribed. Consequently, the transcription and translation can be coupled in bacteria.”