Which flap setting is least likely to aid in decreasing landing distance?

Using no flaps, which is referred to as 0% flaps, is the setting least likely to aid in decreasing landing distance. Flaps are deployed to increase lift at lower speeds, which allows an aircraft to land at a slower speed and thus reduces the distance required to land. When flaps are extended, they change the airflow characteristics over the wings, which facilitates a steeper descent angle and reduced stall speed.

At 100% and 50% flap settings, the aircraft is capable of landing more efficiently because these configurations enhance lift and drag, making for a shorter landing run. On the other hand, not using flaps at all means the aircraft has to maintain higher speeds during landing, which requires a longer distance to stop after touchdown. Therefore, the 0% flap setting significantly diminishes the effectiveness of the aircraft's landing performance. This is why this choice stands out as the least effective option for minimizing landing distance.