Correct Option: B

Natural genetic transformation is believed to be the essential mechanism for the attainment of genetic plasticity in many species of bacteria. During bacterial evolution, the ability of Bacteria and Archaea to adapt to new environments most often results from the acquisition of new genes through horizontal transfer rather than by the alteration of gene functions through numerous point mutations. Horizontal gene transfer is defined to be the movement of genetic material between bacteria other than by descent in which information travels through the generations as the cell divides. It is most often thought of as a sexual process that requires a mechanism for the mobilization of chromosomal DNA among bacterial cells. However, because they are unable to reproduce sexually, bacterial species have acquired several mechanisms by which to exchange genetic materials. It can happen through transformation, conjugation and transduction. In bacteria, it mainly occurs by transformation and conjugation.