What type of dismount yields a high degree of difficulty and consists of a back salto with three twists?

The type of dismount that yields a high degree of difficulty and consists of a back salto with three twists is indeed represented by the choice that describes a back salto with a specific number of twists. In gymnastics, a "back salto" refers to a backward flip, and the mention of three twists indicates a complex maneuver that showcases the gymnast's skill and precision.

Twists in dismounts add significant difficulty due to the required rotational control and spatial awareness. Performing three full twists in a back salto demonstrates advanced technique and execution, which are critical components that judges look for when assessing a gymnast's performance.

The other options do not adequately reflect the combination of a back salto with three twists, which is essential for identifying this specific dismount as one that scores high on the difficulty scale. Each of those options represents different types of dismounts, either focusing on double flips or other twisting configurations that do not match the description provided in the question. Thus, the correct answer highlights both the intricate nature of the twist and the type of salto, making it the best representation of a high-difficulty dismount.