What construction system is characterized by supporting heavier loads at longer spans than the flat slab system?

The waffle slab system is designed to support heavier loads and is capable of spanning longer distances compared to a flat slab system. This is primarily because waffle slabs use a grid of ribs that provide structural strength and distribute loads more efficiently across the slab. The pattern of voids, or "waffles," reduces the amount of concrete needed without sacrificing load-bearing capacity.

Due to this ribbed design, waffle slabs can achieve significant spans—making them suitable for large open spaces such as auditoriums or commercial buildings where floor-to-floor heights may be necessary. This capability allows for more flexibility in architectural design and usage of the interior space.

In contrast, flat slabs, while simpler in construction and more economical for shorter spans, do not have the same load-bearing efficiency. The other choices presented do not typically focus on longer spans with heavier loads as effectively as waffle slabs do.