Which mirror helps with visibility on both sides of the bus?

The correct choice encompasses all options because they each contribute to the visibility on both sides of the bus in distinct ways. A convex mirror offers a wider field of view compared to flat mirrors, allowing drivers to see objects that might otherwise be out of view in regular mirrors. This feature is particularly beneficial for spotting pedestrians or vehicles approaching from the side.

Flat mirrors are also vital as they provide a true distance view, allowing the driver to accurately judge the space around the bus, especially when merging or changing lanes. The right and left side view mirrors play a crucial role by giving direct visibility of the areas alongside the bus, which is essential for safe maneuvering.

Using all these mirrors in conjunction provides comprehensive visibility, ensuring that the driver is well-informed about their surroundings and can operate the bus safely and effectively.