The right answer is A) nucleus, cytoplasm, ribosome.
Expression of a gene in protein involves two steps, transcription and translation. During transcription, an intermediate molecule, the messenger RNA (mRNA), whose sequence is complementary to that of DNA, is synthesized in the nucleus under the action of an enzymatic complex, RNA polymerase.
The second stage, translation, takes place in the cytoplasm and corresponds to the actual biosynthesis of the protein. This synthesis, carried out according to the program contained in the mRNA, is carried out by ribosomes, cytoplasmic organelles about fifteen nanometers in diameter, formed of a building of proteins and RNA.
The mRNA is "read" by the ribosomes that chain the amino acids into a polypeptide chain during enzymatic reactions. The translation of an mRNA starts at an initiation codon and ends at a stop codon.