The right answer is C
Molecular biology and genetic engineering are at the basis of biotechnologies, in particular those based on recombinant DNA and genetic transformations.
It consists of introducing a gene into a DNA ring (plasmid). This plasmid is then transferred to bacteria. For example, if a human gene is introduced into a bacterium, it will produce the corresponding human protein, which is then isolated from bacteria, purified and ultimately used as a substitute drug.