Final answer:
Generating new words while driving is an active cognitive task that likely impairs performance due to increased cognitive load, as opposed to passive listening which demands less cognitive effort and should affect driving performance minimally.
Step-by-step explanation:
The question revolves around cognitive load and distraction while driving. The need to generate new words during driving is a task that requires active cognitive processing and is likely to impair performance compared to passive listening, which is less demanding. When we compare this scenario to the provided information where performance was almost as good with belief in substance intake as with actual consumption, it suggests that belief can boost performance, but generating words is an active task that competes with driving for cognitive resources, which generally impairs driving performance.
The correct answer is c) Performance is impaired. Active tasks like word generation during driving increase cognitive load and can lead to decreased attention on driving tasks, thereby impairing performance. In contrast, passive listening does not significantly increase cognitive load and is less likely to affect driving performance.