What is the ratio of maximum shear stress to average shear stress for a circular section ?

• A. 2
• B. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/92-562-1.png">
• C. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/15-1236-4.png">
• D. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/15-1235-4.png">