The correct option is A Both assertion and reason are correct and reason is the correct explanation of assertion
Recombinant DNA technology is the technology used to alter the genome of a living cell for obtaining the product of interest. For example, in the field of medical science, the precursor of hormone insulin, proinsulin, is produced at a large scale using the recombinant DNA technology.
In this process, the desired gene is incorporated into a plasmid vector. The recombinant plasmid DNA is transferred into any host cell like bacteria (E.coli) or yeast. The selection of host cells is done such that they multiply rapidly to form a huge population and each clone expresses the human gene. Both bacteria and yeast multiply rapidly to form a huge biomass. The product can be extracted from the culture media by appropriate methods.
Hence, both assertion and reason are correct and reason is the correct explanation of assertion.