Correct option is D
An
R.C.C. roof slab is classified as a
two-way slab when it is supported on all four edges and the ratio of the longer span (L) to the shorter span (B) is
less than 2 (L/B<2).
Key Characteristics:
1. Two-way slabs:
The load is distributed in both directions (longer and shorter spans).
Reinforcement is provided in both directions.
2. One-way slabs:
The load is primarily distributed along the shorter span direction.
Occurs when L/B≥2.
