When a circular beam of diameter d is subjected to a shear force F, the maximum shear stress induced will be

• A. <img src="/_files/images/mechanical-engineering/machine-design/562-75-1.png">
• B. <img src="/_files/images/mechanical-engineering/machine-design/562-75-2.png">
• C. <img src="/_files/images/mechanical-engineering/machine-design/562-75-3.png">
• D. <img src="/_files/images/mechanical-engineering/machine-design/562-75-4.png">