Final answer:
The process where the base sequence of an RNA molecule directs the synthesis of a protein is called translation, which comes after transcription, where DNA is copied into mRNA.
Step-by-step explanation:
This essential step in gene expression occurs after the process of transcription, where a DNA segment is copied into messenger RNA (mRNA).
The mRNA then serves as a template for the synthesis of a protein, with the aid of the cell's ribosomes and transfer RNA (tRNA).
It is during translation that the sequence of bases in the mRNA molecule is decoded into a sequence of amino acids, forming a polypeptide chain that folds into a functional protein.
To clarify some of the options presented in the question:
Replication is the copying of DNA to produce two identical DNA molecules.
Transcription is the formation of RNA from a DNA template.
Reverse transcription involves the synthesis of DNA from an RNA template, which is not involved in protein synthesis and is used by certain viruses.