To Make a Drug Testing Policy Legally Strong and Effective

To make a drug testing policy legally strong and effective in the workplace, what is a good idea if an employee fails a drug test?

A) fire the employee immediately
B) fire the employee immediately and report the results of the test to relevant law enforcement authorities
C) warn the employee that if there is another failure, it will lead to serious problems
D) allow the employee to take a second, high-quality test to eliminate false positive readings
E) all of the other choices are fine legally