Asteel rod whose diameteris 2 cm and is 2 m long, experiences heating of temperature $$30^\circ C$$ to $$150^\circ C$$. The coefficient of thermal expansion is $$\alpha = 12 \times 10^{-6}/ ^\circ C$$ and Young's modulus is 200 GPa. If the rod has been restricted to its original position, then the thermal stress (MPa) developed will be ................

A

234

B

256

C

288

D

300