What must a school bus driver do before making a turn?

A school bus driver must check mirrors before and during a turn to ensure the safety of all passengers and pedestrians in the vicinity. This practice allows the driver to maintain awareness of their surroundings, including the position of other vehicles, cyclists, and pedestrians, which is crucial when operating a large vehicle like a school bus.

By checking mirrors before making a turn, the driver can identify any potential hazards that may not be visible directly in front of them. Checking during the turn provides real-time feedback on the bus's position relative to obstacles and other road users, ensuring safe maneuvering. This two-step approach is essential for maintaining a high level of safety when turning, especially in areas where children may be present, such as school zones or residential neighborhoods.

The other options do not provide comprehensive safety strategies. For instance, signaling for a mere five seconds may not give adequate notice for other drivers and pedestrians to react, while checking mirrors just once fails to capture the dynamic nature of the environment as the turn is executed. Announcing an intention to turn, while helpful in some scenarios, is not a requirement and does not replace the critical visual checks that ensure safety.