What is a key reason for exercising caution near children on bicycles?

Exercising caution near children on bicycles is critical because they may act unpredictably. Children are often not fully aware of their surroundings, have developing motor skills, and may not fully comprehend the rules of the road. This unpredictability can lead them to change direction suddenly, swerve unexpectedly, or misjudge distances regarding oncoming traffic. Being aware of this behavior helps drivers remain vigilant and prepared for unexpected actions, ensuring a safer environment for both children and drivers.

The other options don't accurately reflect the behaviors of children. Children are not always accompanied by adults, and even when they are, adults might not be able to prevent all unpredictable actions. They do not consistently look out for vehicles, as their focus might be on play or their immediate surroundings rather than traffic. Lastly, while some children may have begun learning traffic laws, they do not always know all the rules, which can lead to further unexpected behaviors on the road.