Which of the following scenarios qualifies for a DUI according to ARS 28-1381A.3?

The scenario that qualifies for a DUI according to ARS 28-1381A.3 involves having cocaine metabolites in the system while driving. This statute specifically addresses the presence of controlled substances in the driver's system, stating that a person can be considered impaired if they have illegal drugs or their metabolites detectable while driving. This reinforces the notion that impairment does not solely rely on alcohol consumption but also extends to the influence of illegal substances, which can affect a person's ability to operate a vehicle safely.

In the context of the other options, driving with a BAC of 0.06 would not typically qualify for a DUI under most interpretations of the law, as the threshold for impairment is generally higher, often set at 0.08 in many jurisdictions. Regarding prescription medications, simply having taken a prescription that is not affecting the ability to drive does not lead to a DUI charge unless there is evidence of impairment. As for drinking alcohol before driving, without evidence of impairment or an elevated BAC, this situation alone does not meet the criteria for a DUI charge under this statute. Therefore, the only definitive scenario that constitutes a DUI according to ARS 28-1381A.3 is driving with detectable cocaine metabolites in the system.