A steel rod, 2 m long, is held between two walls and heated from 20°C to 60°C. Young’s modulus and coefficient of linear expansion of the rod material are 200 × 103 MPa and 10 × 10-6/°C respectively. The stress induced in the rod, if walls yield by 0.2 mm, is

• A. 60 MPa tensile
• B. 80 MPa tensile
• C. 80 MPa compressive
• D. 60 MPa compressive