What is most likely indicated by the fact that the number of species resistant to a class of herbicide des not decrease over time? a. Individual weeds evolve herbicide resistance and pass the trait to their offspring.

b. The herbicide resistance trait is maintained in resistant populations.

c. The weed populations frequently lose then evolve a resistance to herbicides again.

d. Whenever one weed species loses herbicide resistance, one or more species gains resistance, leading to a net increase in resistant species.