A scientist treats a population of bacteria with a combination of mutagens, including high-energy radiation and certain chemicals. Which is the MOST LIKELY benefit of this treatment? A. The genetic variation of the population decreases, allowing the bacteria to be easier to kill. B. The genetic variation of the population increases, and some of the mutants may have useful properties. C. Many bacterial genes are deactivated, making the bacteria less harmful. D. The bacterial genome increases in length, and some of the new genes may have useful products.