Which of the following defines a prokaryote's intrinsic termination signal?

A short RNA sequence found in the untranslated region (UTR) of mRNA in prokaryotes.

A long sequence of adenine nucleotides that is added to the 3' end of a messenger RNA (mRNA).

A GC-rich sequence followed by a series of many uracil residues in the nascent RNA.

A poly(A) tail that is added to the 3' end of the RNA transcript.