A beam has a solid circular cross-section having diameter d. If a section of the beam is subjected to a shear force F the maximum shear stress in the cross-section is given by

• A. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/11-110-1.png">
• B. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/11-110-2.png">
• C. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/11-110-3.png">
• D. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/11-110-4.png">