The correct answer is: C. Steel is higher than that for concrete.
A factor of safety is a margin of error that is built into a design to account for uncertainties in the loads and material properties. The factor of safety for steel is typically higher than that for concrete because steel is a stronger material. This means that steel can withstand more load before it fails, so a lower factor of safety is required.
Concrete, on the other hand, is a weaker material. It is more susceptible to cracking and deformation under load. Therefore, a higher factor of safety is required to ensure that concrete structures are safe.
The factor of safety for a particular structure will depend on a number of factors, including the type of structure, the loads it will be subjected to, and the material properties. However, in general, the factor of safety for steel is higher than that for concrete.
Here are some additional details about each option:
- Option A: Steel and concrete are same. This is not correct because the factor of safety for steel is typically higher than that for concrete.
- Option B: Steel is lower than that for concrete. This is not correct because the factor of safety for steel is typically higher than that for concrete.
- Option C: Steel is higher than that for concrete. This is the correct answer because steel is a stronger material than concrete and can therefore withstand more load before it fails.
- Option D: None of the above. This is not correct because one of the options is correct.