What action should be taken when you approach a school bus with its stop sign extended?

Answer: C — Stop until the sign retracts

When you approach a school bus with its stop sign extended, the correct action is to stop until the sign retracts. This is a critical safety measure designed to protect children getting on or off the bus. The extended stop sign indicates that children may be crossing the road, and stopping ensures that they have a safe environment to do so. Failing to stop when a school bus has its stop sign extended can lead to serious consequences, including fines and penalties, as well as the potential for injury to children. It's essential to be vigilant in these situations, as children can be unpredictable and may not always be visible. Therefore, stopping not only complies with the law but also plays a crucial role in maintaining the safety of all road users.