What Did the Court Rule Regarding the Reasonableness of Drug

What did the court rule regarding the reasonableness of drug testing?

A) Drug testing is reasonable only when one has given consent,and not under and other circumstances.
B) Drug testing is reasonable because of the random nature of testing and the special need of the government to protect public safety,which outweighs the minimal invasion of privacy.
C) Drug testing is no longer allowed and is a direct violation of the Fourth Amendment.
D) Drug testing is only allowed in those circumstances where the employee consents to submit to the specific tests of his/her urine,not of a random sampling of all employees.