A solid circular shaft of diameter d is subjected to a torque T. The maximum normal stress induced in the shaft, is

• A. zero
• B. <img src="/_files/images/civil-engineering/strength-of-materials/140-6.219-1.png">
• C. <img src="/_files/images/civil-engineering/strength-of-materials/140-6.219-2.png">
• D. none of these.