Which mirrors must be adjusted to enhance visibility while driving a bus?

To enhance visibility while driving a bus, adjusting the outside left and right side convex mirrors is crucial. These mirrors are specifically designed to eliminate blind spots and provide a wider field of vision around the bus, which is necessary for safely navigating traffic and ensuring the safety of passengers.

Convex mirrors on the sides allow the driver to see areas that are not visible in standard flat mirrors, helping to prevent collisions during lane changes and turns. They reflect a larger area and help drivers monitor passenger behavior as well, which is critical in maintaining safety within and around the bus.

While the rearview mirror and interior convex mirrors can aid in visibility, they do not provide the extensive coverage that outside convex mirrors offer. The outside mirrors are vital when it comes to making informed driving decisions in the context of a larger vehicle like a bus, emphasizing their importance over the other options provided.