A metal rod is rigidly fixed at its both ends. The temperature of the rod is increased by 100°C. If the coefficient of linear expansion and elastic modulus of the metal rod are $10\times 10^{-6}mm/_{}^{0}\textrm{C}$ and 200 GPa respectively, then what is the stress produced in the rod?
(a) 100 MPa (tensile)
(b) 200 MPa (tensile)
(c) 200 MPa (compressive)
(d) 100 MPa (compressive)