Correct option is C
There are two limit states
1. Limit state of collapse
2. Limit state of serviceability
i) Limit state of collapse: The limit state of collapse of the structure or part of the structure
could be assessed from rupture of one or more critical sections and from buckling due to elastic or plastic instability or overturning. Limit state of collapse deals with the strength and stability of structures subjected to the maximum design loads out of the possible combinations
Note:
The resistance to bending, shear, torsion, and axial load at every section shall not be less than the appropriate values at that section produced by the most unfavorable combination of loads on the structures using the appropriate partial safety factors
ii) Limit state of serviceability: It ensures that your designed structure is comfortable and
useable enough for human use.
Note:
The serviceability limit state deals with vibrations and deflections (movements), as well
as cracking and durability. It might also involve limits to non-structural issues such as fire, acoustics and heat transmission.
