A steel frame is shown in the given figure.If joint O of the frame is rigid, the rotational stiffness of the frame at point O is given by

• A. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/56-353-1.png">
• B. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/56-353-2.png">
• C. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/56-353-3.png">
• D. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/56-353-4.png">