9) many gardeners use a chemical weed-killer to control plant pests in their gardens. however, many weeds have begun to develop a resistance to these chemical poisons. this is an example of in action.

This is an example of natural selection in action.

Explanation:

    The action of natural selection consists in selecting individuals more adapted to a given ecological condition, eliminating those disadvantaged for that same condition. The most appropriate expression refers to the greater probability of a given individual surviving and leaving descendants in a given environment.

answer; the correct answer is (beta)