Which item is present on the Left Nonessential Bus?

The Left Nonessential Bus is designed to provide power to systems that are not critical for the safe operation of the aircraft, allowing essential systems to retain priority during a failure or malfunction. In this case, the left landing light is powered by the Left Nonessential Bus, which is why it is the correct choice. Nonessential items, such as certain lights, can be shut down or selectively powered to conserve resources and ensure that essential systems remain operational in the event of a power distribution issue.

The right defog blower, radar, and right wiper are typically powered by other buses, such as the Essential or Right Nonessential Bus, which account for system design that separates essential functions from those considered noncritical. By placing systems like the left landing light on the Left Nonessential Bus, aircraft designers can facilitate more efficient power management and ensure that critical avionics and systems maintain operational integrity.