Which theoretical risk accompanies driving after using cannabis?

Driving after using cannabis poses significant theoretical risks primarily due to its effects on cognitive and motor functions. Cannabis use has been shown to impair both concentration and reaction times. This means that individuals may find it more challenging to focus on the road, respond quickly to unexpected situations, or make sound judgments while driving. Impaired reaction times translate to a delay in a driver's ability to respond to changes in traffic conditions or to react to hazards, which can lead to dangerous driving scenarios. As such, option C correctly reflects the adverse effects of cannabis on driving ability, making it a serious concern for road safety.