Concept:Artificially selecting only organisms with preferred traits requires stopping those without such traits from passing on their genes.Explanation:Sterilization is a direct method of making an individual incapable of reproducing.This ensures that undesirable traits are not inherited by future generations.Outbreeding and inbreeding are breeding systems that do not block reproduction.Genetic engineering changes an organism's DNA rather than preventing mating.Therefore, sterilization is the practical way to control which traits appear in the next generation during artificial selection.Answer:B. sterilization