Introduction:
The Working Stress Method is a design approach used in civil engineering to determine the strength and stability of structures. It involves predicting the behavior of materials under different loads and stresses. This method is based on the concept of working stress, which is the stress that the material can safely withstand without significant deformation or failure.

Explanation:
A) Predicts true margin of safety:
The Working Stress Method aims to predict the true margin of safety by considering the working stress levels that the material will experience during its service life. This helps in designing structures that can safely withstand the expected loads and stresses without failure.

B) Considers ultimate stress as the limit of safety:
In the Working Stress Method, the ultimate stress of the material is not considered as the limit of safety. Instead, a factor of safety is applied to the working stress to ensure that the structure can tolerate unexpected variations in loads and stresses. This factor of safety takes into account uncertainties in material properties, construction quality, and other factors.

C) Effect of creep and shrinkage is ignored:
One key limitation of the Working Stress Method is that it does not explicitly consider the effects of creep and shrinkage. Creep refers to the time-dependent deformation of materials under constant stress, while shrinkage refers to the contraction that occurs in concrete as it dries. These effects can lead to long-term deformation and cracking in structures and should be considered in design. However, the Working Stress Method does not directly account for these effects.

D) Failure criteria is stress:
In the Working Stress Method, the failure criteria are based on stress levels. The design is considered safe as long as the working stress does not exceed the allowable stress limits defined for the material. This approach assumes that failure is primarily due to excessive stress levels and does not explicitly consider other failure modes such as deformation, instability, or fatigue.

Conclusion:
In summary, the statement that is NOT true with respect to the Working Stress Method is B) considers ultimate stress as the limit of safety. Instead, the method applies a factor of safety to the working stress to account for uncertainties and variations in loadings. Additionally, the method does not explicitly consider the effects of creep and shrinkage, and its failure criteria are based on stress levels.