What is one key action a driver must take while turning a bus?

Exercising caution to ensure safety is a crucial action for a driver while turning a bus. Turning a large vehicle like a bus requires heightened awareness and attentiveness due to its size and the potential for more significant blind spots than smaller vehicles. It is essential for the driver to be mindful of pedestrians, cyclists, and other vehicles that may be in or approaching the intersection.

By exercising caution, the driver not only ensures their own safety but also the safety of others on the road. This includes checking surroundings thoroughly before making the turn, navigating the turn at an appropriate speed to maintain control, and being aware of any potential hazards. Ultimately, this mindset is integral to safe driving practices, especially when operating a large vehicle like a bus, where the consequences of a mistake can be more severe.

The other options do not prioritize safety appropriately, as signaling after entering the turn does not provide adequate warning to other road users. Checking mirrors only after the turn disregards the importance of maintaining situational awareness during the maneuver. Accelerating during the turn can compromise control and stability, especially in a large vehicle, which can increase the risk of accidents.