What Do Desjardins and Duska Say About Drug Testing and Productivity

What do Desjardins and Duska say about drug testing and productivity?

A) They argue that drug use lowers productivity and therefore employers are justified in conducting randomized drug tests.
B) They argue that drug use has no impact on productivity and therefore employers are not justified in conducting randomized drug test.
C) They argue that unless employers can establish a conclusive link between drug use and productivity, randomized drug tests are immoral.
D) They argue that use of drugs is irrelevant; if an employees productivity is unsatisfactory, the employee should be terminated for poor work performance and not for testing positive for drugs.