Soon after the introduction of antibiotics,resistant strains of bacteria that could grow in the presence of particular antibiotics began to evolve.Researchers develop new antibiotics,only to see resistant bacterial strains evolve within a few years.Which of the following explains why resistant strains of bacteria can evolve so quickly?

A)bacteria have a short generation time
B)bacteria can transfer plasmids containing resistance genes via conjugation
C)horizontal gene transfer
D)bacteria have a short generation time and can transfer plasmids containing resistance genes via conjugation
E)bacteria have a short generation time and can transfer plasmids containing resistance genes by horizontal gene transfer mechanisms such as conjugation