A solid steel cube constrained on all six faces is heated so that the temperature rises uniformly by ΔT. If the thermal coefficient of the material is α, Young’s modulus is E and the Poisson’s ratio is v, the thermal stress developed in the cube due to heating is

• A. \(-\frac{{\alpha \left( {{\rm{\Delta }}T} \right)E}}{{\left( {1 - 2v} \right)}}\)
• B. \(- \frac{{2\alpha \left( {{\rm{\Delta }}T} \right)E}}{{\left( {1 - 2v} \right)}}\)
• C. \(- \frac{{3\alpha \left( {{\rm{\Delta }}T} \right)E}}{{\left( {1 - 2v} \right)}}\)
• D. \(-\frac{{\alpha \left( {{\rm{\Delta }}T} \right)E}}{{3\left( {1 - 2v} \right)}}\)