Which condition disqualifies a driver from certification regarding the use of Schedule I drugs?

The use of marijuana disqualifies a driver from certification due to its classification as a Schedule I drug. Schedule I drugs, according to the Controlled Substances Act, are substances that have a high potential for abuse, have no currently accepted medical use in treatment in the United States, and lack accepted safety for use under medical supervision. The presence of such drugs in a driver's system can impair their ability to operate a vehicle safely, posing significant risks to public safety. Therefore, any driver testing positive for marijuana is deemed unfit for certification.

In the context of the other choices, while alcohol, cocaine, and opiates can also impair driving abilities and may lead to disqualification under certain circumstances, they do not align with the strict classification of disqualifying substances as laid out specifically for Schedule I drugs. Specifically, the focus of the question pertains to drugs categorized under that classification which includes marijuana but not the others listed.