The equilibrium equation in Z-direction in terms of effected stress for a saturated soil body is given by __________

• A. \(\frac{∂σ_x{‘}}{∂x}+\frac{∂τ_{yx}}{∂y}+\frac{∂τ_{zx}}{∂z}++γ_w \frac{∂h}{∂z}=0\)
• B. \(\frac{∂τ_{xy}}{∂x}+\frac{∂σ_y{‘}}{∂y}+\frac{∂τ_{zy}}{∂z}+γ_w \frac{∂h}{∂z}=0\)
• C. \(\frac{∂τ_{xz}}{∂x}+\frac{∂τ_{yz}}{∂y}+\frac{∂σ_z{‘}}{∂z}+γ’+γ_w \frac{∂h}{∂z}=0\)
• D. \(\frac{∂σ_x{‘}}{∂x}+\frac{∂τ_{yx}}{∂y}+\frac{∂τ_{zx}}{∂z}=0\)