The correct option is D All of these
Biotechnology involves the various techniques that use live organisms, or their enzymes to produce products that are useful to humans in some way.
The synthesis of a gene, developing DNA based vaccines, and using gene therapies to correct defects in DNA are all techniques/processes included under biotechnology.
PCR (polymerase chain reaction) is one of the methods employed in biotechnology to synthesise multiple copies of a gene.
DNA based vaccines contain DNA that codes for specific proteins (antigens) from a pathogen. The DNA based vaccines are considered safe in comparison to other types of vaccines to prevent various diseases.
Defective/faulty gene is responsible for various genetic disorders. Gene therapy includes methods that allow correction of a defective gene.