Using the connectivity of the elements, the internal virtual work can be expressed in the form _____

(a) Ψ^T=KQ

(b) Ψ^T=K

(c) KQ=F

(d) σ=Dε

I got this question during an internship interview.

The doubt is from Finite Element Modelling in portion Axis Symmetric Solids Subjected to Axis Symmetric Loading of Finite Element Method