All three of those options involve structures determined by “chance” (which is itself a more complicated idea than the simple word suggests, but that doesn’t really matter at the level we’re operating on right now), operating within a designed structure that constrains the possible range that chance can operate on. The end result is in fact determined by both design and chance, operating at the same time. A different design would create different results, even if “chance” operated the same way. The same design might create different results, if “chance” operated differently.
All three of those options involve structures determined by “chance” (which is itself a more complicated idea than the simple word suggests, but that doesn’t really matter at the level we’re operating on right now), operating within a designed structure that constrains the possible range that chance can operate on. The end result is in fact determined by both design and chance, operating at the same time. A different design would create different results, even if “chance” operated the same way. The same design might create different results, if “chance” operated differently.