Why is it dangerous to follow the same vehicle for a long time?

Following the same vehicle for an extended period can lead to a false sense of security, which in turn can cause a driver to become overly relaxed and lose focus on the driving task. When a driver becomes complacent, they might not react as quickly to changing road conditions or unexpected actions by other drivers. This relaxed state can diminish attentiveness, making it easier for the driver to overlook crucial aspects of safe driving, such as maintaining a safe following distance, being alert to traffic changes, or recognizing potential hazards on the road.

While the other options address valid concerns, the emphasis on complacency highlights a critical aspect of driving safety. Being too relaxed can significantly impair a driver's ability to respond effectively, putting them and others on the road at risk. Therefore, the danger of following the same vehicle for too long lies in the tendency to lose caution, leading to potentially hazardous situations.