A beam of square section of side 'a' is plane in the following way :Case I: with two sides horizontalCase II: with a diagonal horizontalThe ratio of the section modulus of Case I that of Case II is

• A. 2
• B. <span class="root">2</span>
• C. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/95-577-3.png">
• D. <img src="/_files/images/civil-engineering/upsc-civil-service-exam-questions/95-577-4.png">