What is the first stage of protein synthesis?
a. the assembly of transcription factors at the promoter elongation, in which amino acids are joined to the polypeptide chain
b. setting the reading frame, where the initiation codon is recognized by RNA polymerase
c. tRNA charging, in which the tRNAs bind to amino acids initiation, in which the components necessary for translation are assembled at the ribosome

b. setting the reading frame, where the initiation codon is recognized by RNA polymerase.

Explanation:

The first step in protein synthesis is called transcription. Transcription is the process wherein DNA is used to create messenger RNA, or mRNA. The mRNA is produced using DNA's code, which is contained within the cell's nucleus. The steps include:

RNA polymerase, together with one or more general transcription factors, binds to promoter DNA. RNA polymerase creates a transcription bubble, which separates the two strands of the DNA helix. This is done by breaking the hydrogen bonds between complementary DNA nucleotides.

RNA polymerase adds RNA nucleotides (which are complementary to the nucleotides of one DNA strand).

RNA sugar-phosphate backbone forms with assistance from RNA polymerase to form an RNA strand.

Hydrogen bonds of the RNA–DNA helix break, freeing the newly synthesized RNA strand. The RNA may remain in the nucleus or exit to the cytoplasm through the nuclear pore complex.