Herbicide A has been used for years in order to kill a particular type of weed. An experiment is to be conducted in order to see whether a new herbicide, Herbicide B, is more effective than Herbicide A. Herbicide A will continue to be used unless there is sufficient evidence that Herbicide B is more effective. The alternative hypothesis in this problem is_____________?

A. Herbicide A is more effective than Herbicide B
B. Herbicide A is not more effective than Herbicide B
C. Herbicide B is more effective than Herbicide A
D. Herbicide B is not more effective than Herbicide A