Answer: The correct option is C.
Cloning vectors.
Explanation:
Viruses are use as cloning vectors because they can give the new gene or birth the new gene by infecting the cell. They are so modified and orogrammed in such a way that they cannot cause disease when it is used in humans. Cloning vector is a DNA fragment gotten from viruses or bacteria plasmid which is maintained and used for cloning purposes.
Synthesis
Your body is in maintaining it's defense and it will do so for as long as you live.
