The correct answer is: A. Less than 1.
A one-way slab is a type of concrete slab that is designed to carry loads primarily in one direction. The long span of a one-way slab is the direction in which the slab is designed to carry loads, and the short span is the direction perpendicular to the long span.
The ratio of the long span to the short span is a factor that is used to determine the type of slab that is required. A slab is designed as a one-way slab if the ratio of the long span to the short span is less than 1.
If the ratio of the long span to the short span is greater than 1, then the slab is designed as a two-way slab. A two-way slab is a type of concrete slab that is designed to carry loads in both directions.
The following are the brief explanations of each option:
- Option A: Less than 1. A slab is designed as a one-way slab if the ratio of the long span to the short span is less than 1.
- Option B: Between 1 and 1.5. A slab is designed as a two-way slab if the ratio of the long span to the short span is greater than 1.
- Option C: Between 1.5 and 2. This option is not correct.
- Option D: Greater than 2. This option is not correct.