What must be done before starting the engine of the school bus?

Answer: B — Conduct a safety check and ensure the area is clear

Before starting the engine of a school bus, conducting a safety check and ensuring the area is clear is crucial for several reasons. This step ensures that the bus is safe to operate and that there are no obstacles or individuals in the vicinity that could pose a danger during the bus's movement. A safety check typically includes verifying that all safety equipment, such as reflective triangles and fire extinguishers, are in place and functional. Additionally, assessing the area helps to ensure that children are at a safe distance and that no one is in front or behind the bus where they might not be seen. Taking this precaution not only protects passengers but also protects other pedestrians and vehicles in the vicinity. Checking fuel levels, ensuring windows are closed, and turning on the lights are important tasks but should not take precedence over making sure the area is clear and that it is safe to start the bus. Ensuring safety before starting the engine is the foundational practice that will mitigate risks and help create a secure environment for everyone involved.