Which of the following scenarios best exemplifies drowsy driving?

The scenario that best exemplifies drowsy driving involves taking medication that causes sleepiness. Certain medications, particularly those that are sedative in nature or have side effects like drowsiness, can significantly impair a person's ability to drive safely. These medications can reduce alertness and reaction times, making it difficult for an individual to respond appropriately to the demands of the road, which is a hallmark of drowsy driving behavior.

While driving with a passenger, having a full night's sleep, and driving with proper ventilation may be conditions related to driving, they do not inherently indicate drowsiness. For example, having a full night's sleep is likely to enhance a person's alertness rather than diminish it, and proper ventilation typically helps keep a driver more awake. Therefore, the use of certain medications that induce sleepiness directly relates to the risk of drowsy driving, making it the most illustrative example of the scenario in question.