In which arrangement does negative space itself become a unit of rhythm?

Correct answer: Repeated empty intervals between identical shapes

Negative space is the unoccupied area surrounding or separating visible forms. When empty intervals recur with a recognizable pattern between identical shapes, those gaps become repeated visual units and guide the eye just as the shapes do. Therefore option B correctly identifies rhythmic negative space. A solid page and a single circle provide no repeated interval, while connected lines eliminate the gaps needed for this effect.