5.For a plane strain problem, the relation between stress and strain components for an orthotropic material is =C . Which option is the correct structure of the matrix C?

• A. ( begin{pmatrix} bar{c}_{11} & bar{c}_{12} & 0 bar{c}_{12} & bar{c}_{22} & 0 0 & 0 & bar{c}_{66} end{pmatrix} )
• B. ( begin{pmatrix} bar{c}_{11} & 0 & bar{c}_{13} bar{c}_{12} & bar{c}_{22} & 0 0 & 0 & bar{c}_{66} end{pmatrix} )
• C. ( begin{pmatrix} bar{c}_{11} & bar{c}_{12} & 0 - bar{c}_{12} & bar{c}_{22} & 0 0 & 0 & bar{c}_{66} end{pmatrix} )
• D. ( begin{pmatrix} bar{c}_{11} & - bar{c}_{12} & 0 bar{c}_{12} & bar{c}_{22} & 0 0 & 0 & bar{c}_{66} end{pmatrix} )